Upgrade dependencies

- maven-compiler-plugin from 3.1 to 3.2
- maven-source-plugin from 2.3 to 2.4
- maven-javadoc-plugin from 2.9.1 to 2.10.1
- coveralls-maven-plugin from 2.2.0 to 3.0.1
- maven-release-plugin from 2.5 to 2.5.1