Mark rebar.config as an Erlang file for Vim.
Exclude the, generated, lexer and parser from coverage report.
Test oauth1_authorization_request module.

TODO: storage errors.
Fix incorrect key upon de-serialization of authorization request.
Replace lists:keysearch/3 with an abstract dictionary lookup.
Replace lists:keysearch/2 with hope_kv_list:get/2
Test oauth1_authorizations module.