Make check-manifest happy

MANIFEST.in

@@ -7,6 +7,7 @@ include .travis.yml
 include testsuite.py
 include tests.py
 include tests/*.txt
+include tests/sample-tree/snake.egg-info
 recursive-include tests/sample-tree *.py *.zip
 
 # added by check_manifest.py

setup.cfg

@@ -8,3 +8,8 @@ python-file-with-version = findimports.py
 extend-ignore = E131
 # https://pep8.readthedocs.org/en/latest/intro.html#error-codes
 # E131: continuation line unaligned for hanging indent
+
+[check-manifest]
+ignore-bad-ideas =
+  .#emacsjunk.py
+  snake.egg-info