fixed PMDWarnings.

fixed md5 checksum error.
Merge pull request #950 from Catrobat/PMDWarningsPart9

fixed PMDWarnings.
issue#813 Added new testcase, fixed bug
Merge pull request #945 from Catrobat/issue#813

issue#813 Added new testcase, fixed bug
Merge branch 'master' into drone2-merge-master
Merge branch 'drone2-merge-master' into drone2
Drone PreStage/Stage and Service Tests