Add basic help info to make file
Add basic help info to make file

Why:

 * I hate reading readme's to discover what I need to do on
   a `makefile` based project.

This change addreses the need by:

 * added basic `help` target that will use `awk` to look for
   ## comment before a task to use as description.

   i.e.
   ```
   .PHONY: test
   ## This runs tests.
   test: go test
   ```
fixes #68
fixes #70

ldimaggi/almighty-core,ldimaggi/almighty-core,ALMighty/almighty-core,ldimaggi/almighty-core,ldimaggi/almighty-core