Fixed range numericality unit tests and added beginning greater than end validation.

Signed off by: Rafael Manzo <rr.manzo@gmail.com>
Added overlapping ranges validation.

Signed off by: Rafael Manzo <rr.manzo@gmail.com>
Fixed overlapping acceptance test for beginning uniqueness and range intersection
Range overlapping does not consider the reange itself for the edition case

Fixed infinity buttons acceptance tests that were trying to create overlapping ranges
Merge pull request #99 from mezuro/range_validations

Range validations