adding code coverage badge.
Fixing test helper requires.
Updating code climate badge.
merged develop into this
Updated todo.
Moved entity tests to rspec.
Updated todo

Marked this point, since there is a good readme, but it needs more
about how you use it.
boyscouted require.
Moved minitest for immutale entitiy to rspec.

Also change the handling of valid and created a error for it.
Moved minitest interactor test to rspec.
Added coverals to rspec tests.
Moving operation test from minitest to rspec.
Fixing spec_helper includes.
Fixing spec_helper requires.
Improved benchmark names.
Converted last mini tests to rspec.
Adding 2.0.0 to TravisCI.
Removing everything related to entities.
Fixed the gemspec, so that it has the correct path for test files.

This was needed after the conversion from mini test to rspec.
Merge upstream from factlink's develop branch