Fix for 'fatal error' when modulePattern matches nothing
Fix for 'fatal error' when modulePattern matches nothing

This error happens when 'modulePattern' is specified, but doesn't match anything. Grunt dies with misterious message:  'fatal error, cannot read property 1 of null'
ModelN/grunt-blanket-mocha,GruntBlanketMocha/grunt-blanket-mocha,4lejandrito/grunt-blanket-mocha,4lejandrito/grunt-blanket-mocha,GruntBlanketMocha/grunt-blanket-mocha,ModelN/grunt-blanket-mocha