Add dependency on an http client to Pslackr class
Revert "Add dependency on an http client to Pslackr class"

This reverts commit 3f05f7e3f8b50c80d45f76d3f08242d791b6e8de.
Fix namespacing of send() arg and add docblock
Implement default transport using Guzzle lib
Update required PHP version in composer.json
Change name of package
Improve composer.json
Add much more info to the Readme