removed label from submit button
added helper test for job offers #56
Merge branch 'develop-ja' into develop
Merge branch 'develop-ja' into develop

Conflicts:
	app/views/job_offers/_form.html.erb
added controller tests for filter in job offer and for matching in student
small refactoring in filter methods in job offer model
Merge branch 'develop' into develop-ja
Merge branch 'develop-ja' of https://github.com/tkowark/hpi-hiwi-portal into develop-ja