Renames Jeckle::Resource.default_api to just Jeckle::Resource.api.

* Add History file markdown to documenting changes.
Deprecating Jeckle::Resource.default_api. Use Jeckle::Resource.api method.
Change default_api to api in Readme.markdown
Merge pull request #38 from tomas-stefano/renaming-api-method-name

Renames Jeckle::Resource.default_api to just Jeckle::Resource.api.