fix regex to allow database names to contain "-" in role@db syntax

Author: dermsd

lib/puppet/type/mongodb_user.rb

@@ -42,7 +42,7 @@ def initialize(*args)
   newproperty(:roles, array_matching: :all) do
     desc "The user's roles."
     defaultto ['dbAdmin']
-    newvalue(%r{^\w+(@\w+)?$})
+    newvalue(%r{^\w+(@[\w-]+)?$})
 
     # Pretty output for arrays.
     def should_to_s(value)