[#48] Add license to gemspec, GPLv3
Remove warnings for test suite

* warning: mismatched indentations at 'end' with 'class' at xxx
* warning: method redefined; discarding old xxx
* warning: assigned but unused variable xxx
* warning: previous definition of xxx was here
* The source :rubygems is deprecated because HTTP requests are insecure. (Gemfile)
spreadsheet-0.8.7.gem released - should be ready for Ruby 2.0.0
Updated Manifest.txt
Update excel/internals.rb to reference a valid Encoding type

Encoding.find("MACINTOSH") was throwing an error. Encoding.find("MACROMAN") does not.
spreadsheet-0.8.8.gem released
Work around to handle number formats that are being mistaken time formats
Merge branch 'number_format' of https://github.com/nestegg/spreadsheet
spreadsheet-0.8.9.gem released
delete worksheet
Updated README for Travis notice
updated .travis.yml
Update Gemfile
added Gemfile.lock
updated spreadsheet.gemspec
updated Gemfile and Gemfile.lock
updated .travis.yml
updated .travis.yml
updated .travis.yml
updated .travis.yml