Initial commit with Bundler gem configuration
Use rspec for testing
Configure client using environment variables

We are using the dotenv gem in development to copy the necessary variables from a .env file into the environment. This will ensure that no unauthorized keys escape into the wild and make it easier to switch between development/testing and production environments.
Use the awesome_print gem for awesome debugging output
Add Suretax::Connection#post and return Suretax::Response

- Use VCR + webmock to stub requests and replay API responses
- Wrap Faraday response in Suretax::Response
- Deserialize Suretax API response body in custom response
Add note about handling errors in the API response
Use simplecov to generate test coverage reports