Error when building custom Opendaylight API by using the Maven archetype

I am trying to create a custom API based on an API tutorial on http://ift.tt/2pDhd6C

What I have done is just making a few changes in following 4 files:

1. HelloProvider.java
2. hello.yang
3. HelloWorldImpl.java
4. impl-blueprint.xml

I am able to compile the folder in impl ,but it failed when I return to the top level directory and build entire ‘hello’. Here is the Error message:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.18.1:test (default-test) on project hello-features: There are test failures.

And I follow the instruction:

[ERROR] Please refer to /home/oscarzhang/.m2/hello/features/target/surefire-reports for the individual test results.

but I really don't know what the report document says. There are too many information there.

I simply know if I execute this:

mvn clean install –DskipTests

it may work, nevertheless there still would be some drawbacks that a beginner couldn't realise. Although I put this way in the 2nd place, it is really kind of you to tell me the specific drawbacks to make it clear.

I really want to know what cause the error. I even doubt that the snapshot type I choose when I use maven to generate a startup archetype could make a difference.

Thanks for your help.