fix bumpversion config to match black style

Author: gonzalocasas

.bumpversion.cfg

@@ -5,13 +5,13 @@ commit = True
 tag = True
 
 [bumpversion:file:docs/conf.py]
-search = version = release = '{current_version}'
-replace = version = release = '{new_version}'
+search = version = release = "{current_version}"
+replace = version = release = "{new_version}"
 
 [bumpversion:file:CHANGELOG.rst]
 search = Unreleased
 replace = {new_version}
 
 [bumpversion:file:src/roslibpy/__version__.py]
-search = __version__ = '{current_version}'
-replace = __version__ = '{new_version}'
+search = __version__ = "{current_version}"
+replace = __version__ = "{new_version}"