Should I be adding the Django migration files in the .gitignore file?
Gitignore the migrations, if You have separate DBs for Development, Staging and Production environment. For dev. purposes You can use local sqlite DB and play with migrations locally.
I would recommend You to create four additional branches:

Master - Clean fresh code without migrations. Nobody is connected to this branch. Used for code reviews only
Development - daily development. Push/pull accepted. Each developer is working on sqlite DB
Cloud_DEV_env - remote cloud/server DEV environment. Pull only. Keep migrations locally on machine, which is used for the code deployment and remote migrations of Dev database
Cloud_STAG_env - remote cloud/server STAG environment. Pull only. Keep migrations locally on machine, which is used for the code deployment and remote migrations of Stag database 
Cloud_PROD_env - remote cloud/server DEV environment. Pull only. Keep migrations locally on machine, which is used for the code deployment and remote migrations of Prod database

Notes:
2, 3, 4 - migrations can be kept in repos but there should be strict rules of pull requests merging, so we decided to find a person, responsible for deployments, so the only guy who has all the migration files - our deploy-er. He keeps the remote DB migrations each time we have any changes in Models.
Should I be adding the Django migration files in the .gitignore file? 
I've recently been getting a lot of git issues due to migration conflicts and was wondering if I should be marking migration files as ignore. 
If so, how would I go about adding all of the migrations that I have in my apps, and adding them to the .gitignore file?