fixed task dependency order

Task compileRetrolambdaTest was dependent on classes task. Due to this executing of this task caused only building of main source tree.
If "test" task was run, tests weren't processed and was at java1.8 class file format

old build order:

:compileJava UP-TO-DATE
:processResources UP-TO-DATE
:classes
:compileRetrolambdaMain UP-TO-DATE
:compileRetrolambdaTest UP-TO-DATE
:compileRetrolambda UP-TO-DATE
:compileTestJava UP-TO-DATE
:processTestResources UP-TO-DATE
:testClasses UP-TO-DATE
:test UP-TO-DATE

new build order:

:compileJava UP-TO-DATE
:processResources UP-TO-DATE
:classes
:compileRetrolambdaMain UP-TO-DATE
:compileTestJava UP-TO-DATE
:processTestResources UP-TO-DATE
:testClasses UP-TO-DATE
:compileRetrolambdaTest UP-TO-DATE
:compileRetrolambda UP-TO-DATE
:test UP-TO-DATE
upd for prev commit