WIP - fix testing database connection.

Merge pull request mikebronner#282 from GeneaLabs/feature/update-to-l…

…aravel-6

Add Laravel 6.0 support.

Update changelog

Add publish command, fix flushing of pivot releationships, fix detect…

…ion if cache is disabled

Added config and environment variable to allow removal of database in…

…formation from cache-key

Change environment variable `MODEL_CACHE_DISABLED` to `MODEL_CACHE_EN…

…ABLED` to better conform to standards

Fixes mikebronner#266

Remove use of helper methods

Fixed wheretest

Merge branch 'master' of github.com:GeneaLabs/laravel-model-caching

Updated changelog