A cookbook article on how to test forms
Remove --dev, replace AbstractType by FormTypeInterface
Add missing semicolon
Merge branch 'cookbook/form/unit-testing' of github.com:marekkalnik/symfony-docs into marekkalnik-cookbook/form/unit-testing
[#2012] Proofreading the new unit testing form types chapter
Merge branch 'marekkalnik-cookbook/form/unit-testing' into 2.1