Display Support for Swift Package Manager with badge in readme!

Add Package manager support

Update .travis.yml

Start using a ChangeLog to keep track of project changes for future releases.

Provide a convenience implementation for `of(size:)` 

Double

Uniformly include license as comment at the top of every source file.

Update year to 2016-2017 on license

[swiftlint] disable swiftlint rule `type_body_length`

Make usage section more concise

Update .travis.yml

Travis CI sometimes has multiple simulator options for the same `OS` and device `name` so not specifying an explicit `id`
would sometimes cause an ambiguity but recently that issue seems to have been fixed. 

Not explicitly specifying an `id` is more flexible and CI should break less often.

Clean up README.md a bit, bump displayed swift version to `3.1.1`

Update swiftlint line length setting, disable file length rule.

Update podspec version to reflect current release.

Feature for custom fonts

Include tests in swiftlint check and fix violations

and fix violations.

Update CI settings

Update .travis.yml

It looks like the `id` of the simulator device I was using changed, updating the ID should fix it.

Update swift version

Silence swiftlint warning and update rules