Version 0.1.0

Made the dependency on minimist an optional one.

Brought the documentation (README.md) up to speed with the current state of the code.

PURRL REPL
- Updated the default configuration to make the REPL more convenient out of the box

PURRL client
- Many small "polishing" improvements
- Renamed the "query" configuration option to "param"
- Changed the behavior of purrl.config('param', <<Object>>) to be more consistent. It now
  adds options and does not remove options missing from the object.
- Added the "removeParam" configuration option
- Added the "header" and "removeHeader" configuration options
- Added the header() method to specify transient headers
- Added the noHeader() method to temporarily suppress persistent headers
- Added the param() method to specify transient query parameters
- Added the noParam() method to temporarily suppress persistent query parameters
- The request path is now built using the following data
  - Path elements - specified by calling purrl as a function
  - Persistent query parameters - specified using the "param" configuration option
  - Transient query parameters - specified using the param() method
- The request headers are now build using the following data
  - Persistent headers - specified using the "header" configuration option
  - Transient headers - specified using the header() method
- The following hooks are now configurable and are executed during the request/response
  lifecycle:
  - beforeRequest
  - onRequest - new
  - onRequestError
  - beforeRequestBody - new
  - onResponse - new
  - onData
  - onBody
- Refactored the instantiation logic into module local functions
- Added logic to send a request body
- The following verb methods are now available
  - get()
  - post() - new
  - put() - new
  - patch() - new
  - delete() - new
- Added default configuration to the purrl client to automatically detect a body of type
  Object or Array, stringify it, and set the Content-Type header to 'application/json'