release/2.2.0

1. Make all nil values in the response wrap as optional values.
2. Fix routeIndex not working in [NavigationViewController.init].
3. Initialize the instrumentation system in production.
4. Fix reroute logic in navigation and optimize the off-route detection system.
5. Fix crash issue in simulation mode.

release/2.1.0

1. Add 'allow' parameter in route request options
2. Add support for the avoid parameter type to be List
3. Refactor voice speech to support custom speech Synthesizer

2.0.0: Merge pull request #29 from nextbillion-ai/update/1.6.1

Bump to 1.6.1

Merge pull request #29 from nextbillion-ai/update/1.6.1

Bump to 1.6.1

Merge pull request #28 from nextbillion-ai/update/1.6.0

Bump to 1.6.0

1.5.1: Merge pull request #26 from nextbillion-ai/update/1.5.0

Upgrade framework to 1.5.0

Merge pull request #26 from nextbillion-ai/update/1.5.0

Upgrade framework to 1.5.0

Merge pull request #25 from nextbillion-ai/update/1.4.8

Update framework to 1.4.8

1.4.7: Merge pull request #24 from nextbillion-ai/framework_upgrade

Upgrade framework to 1.4.7

Merge pull request #22 from nextbillion-ai/1.4.6

Bump to 1.4.6