tinyprog: Ignore pip-wheel-metadata

"pip-wheel-metadata" is created alongside setup.py, by "pip install ."
(used for development).

See pypa/pip#6213 for discussion of this
clutter (issue currently open; might be moved to another location,
eg build/pip-wheel-metadata or .pip-wheel-metadata, in a later version).

programmer/.gitignore

@@ -9,6 +9,10 @@ __pycache__/
 *~
 tinyprog/full_version.py
 
+# due to pip install . (for development)
+# https://github.com/pypa/pip/issues/6213
+pip-wheel-metadata
+
 # due to using tox and pytest
 .tox
 .coverage