why failed in bgp-linkstate-config when I build BGPCEP?

Hi:
I am a learner of sdn.When i build BGPCEP,it's allow failed in bgp-linkstate-config.Can you help me ??

[ERROR] Failed to execute goal on project bgp-linkstate-config: Could not resolve dependencies for project org.opendaylight.bgpcep:bgp-linkstate-config:bundle:0.3.1-SNAPSHOT: The following artifacts could not be resolved: org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT, org.opendaylight.bgpcep:bgp-parser-spi-config:jar:tests:0.3.1-SNAPSHOT: Failure to find org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT in http://nexus.opendaylight.org/content/repositories/opendaylight.snapshot/ was cached in the local repository, resolution will not be reattempted until the update interval of opendaylight-snapshot has elapsed or updates are forced -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal on project bgp-linkstate-config: Could not resolve dependencies for project org.opendaylight.bgpcep:bgp-linkstate-config:bundle:0.3.1-SNAPSHOT: The following artifacts could not be resolved: org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT, org.opendaylight.bgpcep:bgp-parser-spi-config:jar:tests:0.3.1-SNAPSHOT: Failure to find org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT in http://nexus.opendaylight.org/content/repositories/opendaylight.snapshot/ was cached in the local repository, resolution will not be reattempted until the update interval of opendaylight-snapshot has elapsed or updates are forced
at org.apache.maven.lifecycle.internal.LifecycleDependencyResolver.getDependencies(LifecycleDependencyResolver.java:220)
at org.apache.maven.lifecycle.internal.LifecycleDependencyResolver.resolveProjectDependencies(LifecycleDependencyResolver.java:127)
at org.apache.maven.lifecycle.internal.MojoExecutor.ensureDependenciesAreResolved(MojoExecutor.java:257)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:200)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:108)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:76)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:116)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:361)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:155)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:584)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:213)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:157)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.project.DependencyResolutionException: Could not resolve dependencies for project org.opendaylight.bgpcep:bgp-linkstate-config:bundle:0.3.1-SNAPSHOT: The following artifacts could not be resolved: org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT, org.opendaylight.bgpcep:bgp-parser-spi-config:jar:tests:0.3.1-SNAPSHOT: Failure to find org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT in http://nexus.opendaylight.org/content/repositories/opendaylight.snapshot/ was cached in the local repository, resolution will not be reattempted until the update interval of opendaylight-snapshot has elapsed or updates are forced
at org.apache.maven.project.DefaultProjectDependenciesResolver.resolve(DefaultProjectDependenciesResolver.java:198)
at org.apache.maven.lifecycle.internal.LifecycleDependencyResolver.getDependencies(LifecycleDependencyResolver.java:195)
... 22 more
Caused by: org.eclipse.aether.resolution.DependencyResolutionException: The following artifacts could not be resolved: org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT, org.opendaylight.bgpcep:bgp-parser-spi-config:jar:tests:0.3.1-SNAPSHOT: Failure to find org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT in http://nexus.opendaylight.org/content/repositories/opendaylight.snapshot/ was cached in the local repository, resolution will not be reattempted until the update interval of opendaylight-snapshot has elapsed or updates are forced
at org.eclipse.aether.internal.impl.DefaultRepositorySystem.resolveDependencies(DefaultRepositorySystem.java:384)
at org.apache.maven.project.DefaultProjectDependenciesResolver.resolve(DefaultProjectDependenciesResolver.java:192)
... 23 more
Caused by: org.eclipse.aether.resolution.ArtifactResolutionException: The following artifacts could not be resolved: org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT, org.opendaylight.bgpcep:bgp-parser-spi-config:jar:tests:0.3.1-SNAPSHOT: Failure to find org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT in http://nexus.opendaylight.org/content/repositories/opendaylight.snapshot/ was cached in the local repository, resolution will not be reattempted until the update interval of opendaylight-snapshot has elapsed or updates are forced
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:459)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolveArtifacts(DefaultArtifactResolver.java:262)
at org.eclipse.aether.internal.impl.DefaultRepositorySystem.resolveDependencies(DefaultRepositorySystem.java:367)
... 24 more
Caused by: org.eclipse.aether.transfer.ArtifactNotFoundException: Failure to find org.opendaylight.bgpcep:bgp-rib-spi-config:jar:tests:0.3.1-SNAPSHOT in http://nexus.opendaylight.org/content/repositories/opendaylight.snapshot/ was cached in the local repository, resolution will not be reattempted until the update interval of opendaylight-snapshot has elapsed or updates are forced
at org.eclipse.aether.internal.impl.DefaultUpdateCheckManager.newException(DefaultUpdateCheckManager.java:232)
at org.eclipse.aether.internal.impl.DefaultUpdateCheckManager.checkArtifact(DefaultUpdateCheckManager.java:206)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.gatherDownloads(DefaultArtifactResolver.java:599)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.performDownloads(DefaultArtifactResolver.java:518)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:436)
... 26 more
[ERROR]