Force include source/lib/font-awesome/

[zombie110year]

• The commit message follows our guidelines.
• Tests for the changes was maked (for bug fixes / features).
  • Muse | Mist have been tested.
  • Pisces | Gemini have been tested.
• Docs in NexT website have been added / updated (for new features).

I don't know which type should be chose to describe this change, and it didn't need test.

PR Type

What kind of change does this PR introduce?

• Bugfix.
• Feature.
• Code style update (formatting, local variables).
• Refactoring (no functional changes, no api changes).
• Build related changes.
• CI related changes.
• Documentation content changes.
• Other... Please describe: Modified .gitignore

What is the current behavior?

The origin version was !source/lib/font-awesome/*, but it doesn't work. While I published my blog through Travis CI, It didn't include the font-awersome lib. And my Git GUI told that the dir was excluded by .gitignore.

Issue resolved: #413

What is the new behavior?

Now it works.

Does this PR introduce a breaking change?

• Yes.
• No.

[welcome]

Thanks so much for opening your first PR here!

[CLAassistant]

All committers have signed the CLA.

[ivan-nginx]

Seems it's okey, now please sign CLA and we will merge it. All checks must be passed.

[stevenjoezhang]

Seems this issue: #413 has been resolved?

[zombie110year]

Seems this issue: #413 has been resolved?

Yes, the issue described about what this PR solved. But there isn't font-awesome/dirty directory in the remote repo.

I did't build this repo in local machine and almost know nothing about nodejs, so I don't now whether the directory will be generated by developing tools.

Should add other exclude rule in it?

[ivan-nginx]

@stevenjoezhang pull verified by you?

[stevenjoezhang]

@ivan-nginx Verified.

[welcome]

Congrats on merging your first pull request here! 🎉 How awesome!