Issue/63 - WP-CLI cache/compression toggle commands

[pattonwebz]

Adds a set of simple commands for operating with simple-cache options. Current able to toggle caching on/off and gzip compression on/off using commands in this format:

• wp simple-cache on
• wp simple-cache off
• wp simple-cache on --option=compression
• wp simple-cache off --option=compression
• wp simple-cache on --option=cache
• wp simple-cache off --option=cache

This is a starting point and could be refactored to make it more DRY and to accommodate all of the plugin options. Partial work towards this issue: #63

[pattonwebz]

Hey @tlovett1 you think there is still interest in this one?