Merge branch 'master' of https://github.com/Rekord/rekord

Version 1.5.10

Added load priority

Build 1.5.9

Build for 1.5.8

Add hasTrait to ModelClass, & model instances (resolves #377)

Build for 1.5.6

Add index information to Collection add & remove (resolves #379)

Traits should merge objects with the original objects instead of just…

… methods (resolves #376)

Add Rekord.unload (resolves #375)

Release 1.5.2