Move bumpversion config to .bumpversion.cfg

It seems that bumpversion only bumps the first match in a file,
with no way I can find to get around that. This works around the
problem so that bumpversion works in our setup.py-less world.

.bumpversion.cfg

@@ -0,0 +1,12 @@
+[bumpversion]
+current_version = 0.3.1
+commit = True
+tag = True
+tag_name = {new_version}
+message = New release: {current_version} → {new_version}
+
+[bumpversion:file:.bumpversion.cfg]
+
+[bumpversion:file:qmk_cli/__init__.py]
+
+[bumpversion:file:setup.cfg]

setup.cfg

@@ -1,13 +1,5 @@
-[bumpversion]
-current_version = 0.3.1
-commit = True
-tag = True
-tag_name = {new_version}
-message = New release: {current_version} → {new_version}
-
-[bumpversion:file:qmk_cli/__init__.py]
-
-[bumpversion:file:setup.cfg]
+#[bumpversion]
+# Bumpversion config has been moved to .bumpversion.cfg
 
 [bdist_wheel]
 universal = 1