Create MIT-LICENSE.txt
Avoiding a CCE during form validation, such as when initially configuring a job with both Git SCM and Git Publisher post-build step.
…/job/…/descriptorByName/GitPublisher/checkRemote?value=origin
java.lang.ClassCastException: hudson.scm.NullSCM cannot be cast to hudson.plugins.git.GitSCM
	hudson.plugins.git.GitPublisher$DescriptorImpl.doCheckRemote(GitPublisher.java:419)
Update git-client plugin version dependency to 1.6.1

Use latest released git client plugin so that test builds pass in
BuildHive and elsewhere.
Add jacoco coverage reporting
Merge pull request #190 from MarkEWaite/master-add-jacoco-coverage

Add jacoco coverage reporting and update surefire plugin version
Merge pull request #189 from MarkEWaite/master-update-git-client-version-1.6.1

Update git-client plugin version dependency to 1.6.1
Update pom.xml with MIT license
Merge pull request #186 from vaneyckt/master

Create MIT-LICENSE.txt
Make checkout lock failure retryable.