enforce double quotes (disable in specific projects as needed)

[martinemde]

The result of disabling quote enforcement has mostly fallen into two categories:

1. "yay, now we can require double quotes!"
2. "ugh, our project is so inconsistent, I wish we could just pick one."

Since most of the projects adopting double quotes are smaller projects, we propose changing the default to double quotes, and then disabling directly in the larger apps where switching is painful.

Benefits:

• Consistent, ruby-standard styling (almost everything comes with or generates double quotes)
• New projects automatically stay consistent.
• Old projects don't have to change and can continue to disable quoting rules.

Switching quoting is a reliable and safe autocorrect, so correcting projects that pull code from a single-quoted project into a new project should be painless to correct as part of the rest of the project setup.