Wrap exec paths to configurations in quotes

[JoshuaKGoldberg]

🐛 Bug Report

• tslint-to-eslint-config version: 0.1.7
• ESLint version: N/A
• Node version: N/A

Actual Behavior

If the path to a configuration file provided as a CLI has a space, the internal exec call will treat the portions of the path after the space as extra arguments. That's a crash.

Expected Behavior

Don't do that, please.

Reproduction

tslint-to-eslint-config --eslint "./path with spaces/.eslintrc.js"