* New methods to retrieve Merge Requests with a given status

* improvement of the API to retrieve the Merge Requests

* new method to cherry-pick a commit

* new cherryPick method with a GitlabProject and javadoc

* fixed cherryPick method url and method

* moves MergeRequest status constants

* fixes update/accept Merge Request URLs

* usage of the GitlabMergeRequest constant for the URL

... and every other group creation option that is presently documented.

* #201 initial support for v3 -> v4 api changes.

* Introduce Docker for testing

* Switch to Maven in travis because releases are built with Maven anyway
* Introduce Maven-Wrapper to fixate the used Maven version.
* Reuse existing GitlabAPITest as integration test which will be run
  always when docker is available.
* Use docker-maven-plugin for starting/stopping GitLab.
* For use with Maven run `mvn -Pdocker-gitlab clean verify`. Starting
  GitLab takes a long time (>100 seconds on my Macbook Pro).
* For use in the IDE run:

```
mvn -Pdocker-gitlab,docker-ide docker:start
mvn -Pdocker-gitlab,docker-ide docker:stop
```

* Extract APIForIntegrationTestingHolder

* username/password sessions per time unit are limited

* Need at least source and target 1.7

AssertionError in Tests is only available for >= JDK7

* Use GitlabUploadIT as another integration test

* Don't choke when dockerized SUT is not available

Need to throw AssumptionViolatedException in BeforeClass because
otherwise the class is not initialized correctly.

* Add CONTRIBUTING.md and travis badge.

* Fix API calls for user block/unblock, add some calls

* block/unblock uses POST instead of PUT.
* Add ability to refine permissions for branch protection.
* Add ability to add deploy key with push permission.

* Fix getRawFileContent and getRepositoryTree

* Fix typo

* Do not attempt to map to a Void object

Motivation:

Speed up API calls.

Modifications:

Set maximum per page param when retrieving all results.

Result:

Less calls to GitLab API endpoint when retrieving all results.

* Retrieve version of GitLab API

* Web URL for group

* webUrl in MR

* Date fields

* sha for merge request

* Repository file API

* Added another overloaded version

* Getters and setters

* Missing '/' separator

* Add additional fields for Runner.

The current model is missing some fields.

* Make the User-Agent settable.

This makes it easier to see which program executed requests.

The current model is missing some fields.

* Recursive option on repository tree

* added path attribute to Repoclass

* fixes #167

* fixes #167

* fix author and imports

* fix spacing

* replace tabs with spaces

* better formatting

* Add List of identities under GitlabUser

* Fix UUID. It was UID

Add Service Email-On-Push

https://docs.gitlab.com/ee/api/projects.html#list-branches

Owned projects and project triggers

Deprecating the parameter versions of the createProject, updateProject and createUserProject calls

Changed field deprecated

Changed the 'description' field to 'message' field. The 'description' field it was apparently deprecated.

Build variables implementation

handle NPE when calling GitlabGroup.getLdapAccess()

Conflicts:
	src/test/java/org/gitlab/api/GitlabAPITest.java