3.6

Issue #81: upgrade to checkstyle 7.6
Issue #32: wercker badge was added to README.md
Issue #32: wercker to test installation
Issue #32: basic wercker build file is created
Issue #32: Dockerfile creation for plugin testing in CI
Issue #75: Options for WhitespaceAround too long, type is changed from s[...] to STRING
Issue #45: resolved many checkstyle violations
Issue #45: resolved multiple simple formatting violations
Issue #60: added custom header for project
Issue #71: fix Violation at sonarqube.com
Issue #68: Lessen dependency on Guava
Issue #49: Reduce rule violations