Extract ReviewRunner from Engine for easier testing

Change-Id: Ic8b1ea61285f6c8dfe07d1695524bcee98e70e79
Gradle replacment for sputnik-maven-plugin
updated readme
typo
JSHint support added.
update release link
checkstyle and findbugs tests
Merge pull request #50 from damianszczepanik/launch-with-gradle

Launch with gradle
Merge pull request #51 from gildur/jshint

JSHint support added.
TestEnvironment introduced + refactor
codecov
jacoco + codecov
shields + codecov
merge
Merge pull request #55 from TouK/inc_coverage

Test refactor
- PDM provides now the reason of violation and also gives reason and URL such as http://pmd.sourceforge.net/pmd-5.2.1/pmd-java/rules/java/unusedcode.html#UnusedLocalVariable
- checkstyle and findbugs do not offer such feature out of the box
Added tests and made new feature optional
Added missing file
2nd review
3rd review