JavaMOP only compiles with Java 7?

[owolabileg]

The documentations tells users that JavaMOP requires Java 7 or higher but recent changes to the pom.xml makes it such that JavaMOP can only build on Java 8. Any reasons for this change? The documentation either needs to be changed to reflect this change or we revert the pom.xml file to compile with Java 7 and higher.

[xiaohe27]

@owolabileg I used some JDK 8 features (lambda expression) in the test cases. The JavaMOP itself is OK to compile with JDK 7. I modified the pom in #241 to enable the JDK 7 users to build JavaMOP, and I will modified the docs accordingly.