updated default extension of changelog

release/release_bob.py

@@ -61,7 +61,7 @@ Options:
     -h --help                     Show this screen.
     --version                     Show version.
     -c, --changelog-file STR      A changelog file with all packages to release with their tags, listed in order.
-                                  [default: changelog_since_last_release.rst].
+                                  [default: changelog_since_last_release.md].
     -g, --group-name STR          Group name where we are assuming that all packages are located.
                                   [default: bob].
     -p, --package STR             If the name of a package is provided, then this package will be found