Let's check this in. Can you add a newline at the end first, please?

Some commentary:

• I want to avoid having every contributor adding their own ignore rules to google/python-fire's .gitignore file. See the section on explicit repository excludes for how to additionally ignore files that only apply to you.
• google/python-fire's .gitignore file should only have rules that apply to a very large number of developers. Using GitHub's provided Python.gitignore file sounds good to me. I'm OK w/ adding .idea at the end since PyCharm is common (can you fix the capitalization btw?), though want to be careful not to set a precedent of modifying the .gitignore for individual developers.