Interpreters based on scala_2.11 aren't installed correctly

The pom files of the various interpreters that use Scala 2.11 (e.g. Flink) incorrectly point to Scala 2.10. This results in an incorrect installation when using install-interpreter. Notice the presence of both 2.10 and 2.11 artifacts in the below:

$ bin/install-interpreter.sh --name flink
...
Install flink(org.apache.zeppelin:zeppelin-flink_2.11:0.7.0) to /usr/local/zeppelin/interpreter/flink ... 
Interpreter flink installed under /usr/local/zeppelin/interpreter/flink.
...

$ ls -1 interpreter/flink
...
flink-core-1.1.3.jar
flink-scala_2.11-1.1.3.jar	  
...  
scala-compiler-2.10.5.jar
scala-library-2.10.5.jar
scala-reflect-2.10.5.jar
...

I believe the problem is related to the `scala.binary.version` property, whose value is inherited from the parent POM.

Note that the issue doesn't affect `zeppelin-0.7.0-bin-all.tgz` which has the interpreters correctly pre-installed.