Update many dependencies

Update to many of the dependencies that this library uses:

• Kotlin: 1.3.61 -> 1.6.10
• Ktor: 1.3.1 -> 1.6.7
• kotlin-builder: 1.1.0 -> 1.2.1

Huge thanks to @ssoper and @vadims-grusas for doing the heavy lifting here!

Breaking Changes

See the changelogs for Kotlin and Ktor for a list of breaking changes as a result of dependency updates.
In particular, the use of the experimental Ktor CIO engine no longer works if you're trying to use websocket functionality.
(This should not affect anyone using the default http client when using this library)

What's Changed

• Update ktor an kotlin dependencies by @vadims-grusas in #30

New Contributors

• @vadims-grusas made their first contribution in #30

Full Changelog: v2.0.0...v3.0.0