remove explicit relation from File to Exec in conf.pp

This gets implicitly defined by the notify in the File resource.

compare

http://stderr.at/images/sudo_conf_with_file_exec.png

with

http://stderr.at/images/sudo_conf_without_file_exec.png

or http://docs.puppetlabs.com/puppet/latest/reference/lang_relationships.html
added rspec tests to check file/exec relationship in conf.pp
Merge pull request #61 from tosmi/forsaz

removed explicit resource deps in conf.pp, rspec tests