Gitignore not ignoring env.yml changes

[AbhinandanPadhi]

Tried using the project files without docker (according to the readme), and so the username and password in the env.yml file was changed. The env.yml changes should have been ignored, but I believe they were not, which was an issue when attempting to commit all changes as postgres user name and password may be visible to others.

I believe @abhinavtripathy was working on the .gitignore file recently, so he may need to address this issue.