Make license check warning only for now.
Set default java version to 8.
Change-Id: Idbbc617c739a45bbecbfdd3f8bc394e648b852a8
Signed-off-by: Gary Wu <gary.i.wu@huawei.com>
 
 <module name = "Checker">
     <property name="charset" value="UTF-8"/>
-    <property name="severity" value="error"/>
+    <property name="severity" value="warning"/>
 
     <module name="RegexpHeader">
         <property name="headerFile" value="${checkstyle.header.file}"/>
 
     <module>license</module>
   </modules>
   <properties>
+    <maven.compiler.source>1.8</maven.compiler.source>
+    <maven.compiler.target>1.8</maven.compiler.target>
     <jacoco.version>0.7.7.201606060606</jacoco.version>
     <sonar-jacoco-listeners.version>3.2</sonar-jacoco-listeners.version>
     <sonar.core.codeCoveragePlugin>jacoco</sonar.core.codeCoveragePlugin>