Merge pull request #4 from mgrachev/master

Master into develop
Set the version of ruby into Gemfile
Merge pull request #6 from mgrachev/fix-test

Set the version of ruby into Gemfile
Bump version to 0.3.0
Merge pull request #7 from mgrachev/update-version

Bump version to 0.3.0
Merge pull request #8 from mgrachev/develop

Develop into master