Updated Readme
Added to_pyn and py? methods.

+ Fixed: ZhongwenTools::Romanization.pyn? method now treats spaces
         properly.
+ Added: ZhongwenTools::Romanization.py?; a method for detecting real
         pinyin strings.
+ Added: ZhongwenTools::Romanization.to_pyn; a method for converting
         romanizations to pinyin number format.
+ Added: String.gsub_with_hash; added Ruby 1.9 functionality to Ruby
         1.8's gsub.
+ Gems:  Added pry to test dependencies.
Merge branch 'py_to_pyn' into develop
version 0.7.0
Updated readme
Merge branch 'develop'