Add awesome-lint and CI to lint new awesome lists

[transitive-bullshit]

This PR incorporates awesome-lint and is aimed at providing automated linting to ease the load of reviewing new PRs.

It also adds a .travis.yml file to enable travis-ci testing for PRs.

Note that it is not our intention to fully automate PR reviews, as content is still very important and will always require a manual pass. Instead, we're trying to reduce the amount of time it takes to manually review and maintain the Awesome project.

For new and existing Awesome list authors, lists are not required to pass awesome-lint yet, but it is a good idea to run the linter on your list before submitting, as it will help you find a lot of common issues and will hopefully save us all a great deal of time in the long run.

For more background, see sindresorhus/awesome-lint#39

cc @sindresorhus @itaisteinherz

Fixes #1365.
Fixes #569.
Helps with #1363.

(Edit) Note that this PR is dependent on sindresorhus/awesome-lint#43

[itaisteinherz]

The last two links can be removed from the whitelist since they would be ignored anyways.

[transitive-bullshit]

Good call 😄

[itaisteinherz]

@sindresorhus Would love to see what you think about this and the last 4 comments in sindresorhus/awesome-lint#39.

[sindresorhus]

I'm a bit reluctant of merging this before remarkjs/remark#198 is resolved. It's going to cause a lot of noise. I'm also not sure whether we should have the unordered-list-marker-style rule enabled. Many lists use different style and I don't think it's worth the churn to enforce that.

[sindresorhus]

I'm a bit reluctant of merging this before remarkjs/remark#198 is resolved.

Doesn't look like it will move forward anytime soon. Could we just disable that rule here?

[davisonio]

Like this idea but I've found that some awesome-lint rules are wayy too restrictive. Would be nice if we could disable rules on a per-list basis that are problematic. For example some lists have icons before each awesome item which breaks awesome-lint (as well as my list which for some reason won't recognise the badge even though it's correct).

[itaisteinherz]

as well as my list which for some reason won't recognise the badge even though it's correct

@davisonio It would be great if you could open a specific issue for this over at awesome-lint :)

[sindresorhus]

Moving this to an issue as it has gotten stale: #1619