Merge pull request #4 from mwanji/bugfix_gemspec_platform

Fix "uninitialized constant Gem::Platform::Ruby" error
renamed gem to ta-indicator due to clash with existing gem. Version bump.
Fix typo in readme
Fix indicators that dont require all of ohlcv.

No longer assume that all bar based input indicators require either ohlc or ohlcv. Now all combinations of open, high, low, close and volume will work.

Fixes #5.
Version bump
Merge branch 'master' of github.com:mlamby/indicator
Merge branch 'master' of git://github.com/mlamby/indicator