Change Request to use Resource instead of RestClient
Add user name and password in options
Change command output

- method-command now returns two values: an error
string or a hash containing cli_options, response,
request.
- The return value is forwarded to a pretty
printer object, which in turn returns a string 
that is printed by Pry's output object.
- By modularizing each component, command, output,
and printing, this will allow easy handling of 
different response types (json, xml, etc) and 
different pretty printing (with JQ for example)
Add integration tests with Sinatra

- Built a sample sinatra server used for dev
purposes.
- Record VCR cassettes against the sinatra server
- Clean up requests and commands to reflect
support for different request options.
Add username and password to command-line args