Merge pull request #4 from deric/master

updated readme
Added deb/rh OS detection for correct service naming
Merge branch 'os-detection'
false is an invalid value for PermitRootLogin
Merge branch 'permit-root-fix'
user's and group's definition is looked up all hiera files (using `hiera_hash`)
updated example
updated usage of module
fixed typo
removing user's account
fixed && and exec syntax
order of removing: first user, then group
updated README: removing user's account
groups are also required param
fixed fetching hash, now users should be merged from multiple config files
conditional execution of directory removal
recursive creating of home directories