There was an extra '\' sign in the docker pull command

Updates to travis file, readme and help text

Simply clone the project, compile the go app and run ./cis_kubernetes

* Replace the default help text

* Readme file, including the test config format documentation

* Typo

* Warn if config files / executables aren't found

* Ignore original name of executable (as per current README)

* Update tests to avoid failing on stat of a non-existant file

* Add a makefile for ease of build