64-bit support, updated Mapbox SDK, pin colors

With PR #16 the module now has:

• 64 bit support
• ability to change pin colors
• Updated to latest Mapbox iOS SDK
• Ability to set individual pin colors
• Access mbtiles outside of /Resources directory

With the latest Mapbox iOS SDK, an access token will be required, such as:

mapbox.createView({
  accessToken: 'myAccestokenhere'
...