Improve CDK itests so that user do not need to have all CDK versions downloaded himself

Add mock files that would substitute CDK 2.x Vagrantfile and CDK 3.1.1 binary for purposes of testing UI. These files will be placed in project path in resources/cdk-files.

Let user to pass his vagrant file and cdk-3.1.1 binary path via agrument -Dvagrantfile and -Dminishift in cases where he needs to do so. This argument's values will have priority over files from resources folder.