Merge pull request #3 from SaltShipDesign/master

Fix: When enviroments have $params to false, they get set anyways
Remove param_map. Refs #5

This magic can be confusing to users
Allow `params` to be a callable directly. Refs #5
Return the result of setup() from start()
Return a boolean within Environment::setup()
Remove trailing whitespace
Remove cli check. Closes #4
Move CAKE_ENV check to _match