Use getProjects() instead of getAllProjects()

* Updated GitlabRepository.getProjectForPath() to use the non-admin /projects endpoint
  via GitlabAPI.getProjects(). This allows the use of a user with just the Reporter
  role.
* Updated the Jenkins version in pom.xml.
Updated README.md

Only Reporter access is required for the plug in.
Further updated README.md

* Updated descriptions to be in line with updated Jenkins UI
* Added missing parameters
* Added a note about manual builds not generating comments
Merge pull request #61 from dinosaurjr10/feature/fix-getProjectForPath

Update GitlabRepository.getProjectForPath() to no longer require an admin user