Flake8 cleanup

[Cdiaz1234]

This PR resolves Issue #528 by cleaning up solar.py to comply with flake8 standards.

• Fixed E501 (line too long), E302 (expected blank lines), E231 (missing whitespace), and more
• Ran flake8 to verify all errors are cleared

No functionality was changed — this is a pure style/lint cleanup.

[DWesl]

It looks like the first three commits are for a shiftdata fix you were preparing a month ago: it might be simplest to copy Downloads/.../solar.py somewhere, revert that commit, turn this PR into the shiftdata PR you were preparing, run git checkout upstream/develop -b flake8-solar-cleanup, copy solar.py back to packages/basemap/src/mpl_toolkits/basemap/solar.py, and open a new PR to be the "get flake8 to pipe down about solar.py" one

[DWesl]

Alternately, you might be able to do

cd /path/to/basemap-repository/Downloads/basemap-develop/
git init
git remote add upstream https://github.com/matplotlib/basemap
git fetch upstream
git remote add origin [email protected]:Cdiaz1234/basemap
git fetch origin
git branch flake8-develop
cd packages/basemap/
git add src/mpl_toolkits/basemap/{__init__,solar}.py
git commit
git push --set-upstream --force origin flake8-develop

to turn the unpacked ZIP archive of the repository's develop branch into its own git repository