Fixed gulp-util deprecations

[justin713]

• Replaced gulp-util.log with fancy-log
• Replaced gulp-util.colors with ansi-colors
• Replaced underscore with flat-options
• Added check if options.to is a single email or array of emails
• Removed _subjectFromFilename; use basename if subject not provided
• Removed some extraneous files
• Updated README

Fixes #7. (Thanks for the alert, @JimmyMultani)

[justin713]

@fritx: If you are OK with the changes, are you able to merge, bump version, and push to npm?

[fritx]

Oops @justin713 just a too big commit!
https://crealytics.com/blog/5-reasons-keeping-git-commits-small/

It's a bit better we can change things step by step.

[justin713]

Respectfully, I disagree. We're talking about a commit in which README.md has the highest number of changes. If this were a more complex PR for a more complex issue, I would say, absolutely, yes, let's break it up. But the PR basically only fixes #7, cleaning up some documentation on the way.

If you'd prefer to break it up into two (or more) commits, you can probably cherry-pick from this branch to produce whichever commits you like.

[fritx]

@justin713 i'm probably "an asshole" (if you don't mind) 😄 'cause:

I used git-blame-someone-else to "cheery-pick" part of your commits and published 0.3.0, which could be therefore more predictable (with just a few changes).

After 0.3.0, I would merge the remaining ones. Thanks!