Modified the coverage bullet in the PR template

Title

Edited Coverage check in PR template checklist.

This PR edits the coverage check in the PR template to remove the quantified coverage.

Put an x in the boxes that apply

[ ] Feature (non-breaking change which adds functionality)
[x] Bug Fix (non-breaking change that fixes an issue)
[ ] Breaking Change (feature/fix that causes existing features to not work as expected)
[ ] Documentation

[x] I have read the [contribute]contributing doc
[x] Classes, scripts, and environment variables follow existing naming convention
[x] Lint and Unit tests pass locally
[x] New features on hardware have been tested on a local Raspberry Pi
[x] Mention new programs/binaries if any must be installed along with this change
[x] Mention new environment variables if any have been added to hardware/env file
[x] Test coverage should not drop more than 3%
[x] Any new required python modules are added to the requirements.txt