Added load_dontenv, changed mongo_uri load logic (modmail-dev#59)

* Added load_dontenv, changed mongo_uri load logic

* Updated pipfile.lock

Author: sebkuip

Pipfile

@@ -11,6 +11,7 @@ motor = "~=3.0"
 natural = "~=0.2.0"
 pymongo = {version = "*", extras = ['srv']}  # Required by motor
 python-dateutil = "~=2.8.2"
+python-dotenv = "~=0.18.0"
 sanic = "~=22.6.0"
 
 [scripts]