Adjust booleans in source control modules. (#5158)

plugins/modules/source_control/github/github_key.py

@@ -37,11 +37,11 @@ options:
     type: str
   force:
     description:
-      - The default is C(yes), which will replace the existing remote key
-        if it's different than C(pubkey). If C(no), the key will only be
+      - The default is C(true), which will replace the existing remote key
+        if it's different than C(pubkey). If C(false), the key will only be
         set if no key with the given C(name) exists.
     type: bool
-    default: 'yes'
+    default: true
 
 author: Robert Estelle (@erydo)
 '''