Using the passed jUnit config if set
Using the passed jUnit config if set

Just having a look at this to compare the XML JUnit output to another
JUnit/ PhantomJS task I'm using and noticed that as written it seems to
ignore the passed in JUnit configuration and it's impossible to turn
the JUnit reporting on... 

I think this change makes it behave as expected?
bomatson/grunt-jasmine-node-coffee,jribble/grunt-jasmine-node-coverage,NagrajN/grunt-jasmine-node-coverage-validation,jasmine-contrib/grunt-jasmine-node,fmap-archive/grunt-jasmine-node-multitask,lennym/grunt-jasmine-node