Fix various bugs found in testing before alpha release

-Call mkdir with sudo. Chown the repo back to the calling user after
creating the directory.
-Fix incorrect bash function calls. All echo'd output was being saved in
a variable. This was mucking up the creation of rhel/opt repo variables.
-Give more meaningful output to some of the prompts.
-Install epel before doing anything else
-Add user to the sudoers file as part of bootstrap