我想使用aura框架运行笔记应用程序，但是当我解雇命令时，
mvn jetty:run -X
我收到以下错误。如何解决，
[ERROR] Failed to execute goal on project aura-note:
Could not resolve dependencies for project org.auraframework.demo:aura-note:
jar:0.0.1-SNAPSHOT: Failed to collect dependencies at org.auraframework:aura-util:jar:0.2841:
Failed to read artifact descriptor for org.auraframework:aura-util:jar:0.2841:
Could not transfer artifact org.auraframework:aura-util:pom:0.2841 from/to libs-internal :
maven.auraframework.org: unknown error: Unknown host maven.auraframework.org: unknown error -> [Help 1]