Update test case for multiple group name validation

The group validation function always returns true, regardless of whether or not the groups are valid. This test case adds other permutations.
Fix argument order for $.inArray()

jQuery.inArray( value, array [, fromIndex ] )

_inFieldInGroup() was returning false for ALL field groups, because $.inArray() returns -1 if you mix up the arguments.
Add test cases for HTML5 number input step attribute

The step attribute determines what values should be accepted by an HTML5
number input. If set to "any" or a floating point value, floating point
values should be permitted for the input by the validator.
Use `number` constraint for HTML5 number input if non-int step attribute

HTML5 number inputs allow floating-point numbers if the "step" attribute
is set to "any" or a floating-point number. In this case the appropriate
Parsley constraint would be "number".
Merge pull request #730 from maniacyak/master

Fix validation for fields with multiple group names