Add pull request template including note to run tests on GPU

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,45 @@
+<!--- Provide a general summary of your changes in the Title above -->
+
+## Description
+
+<!--- Describe your changes in detail -->
+
+## Motivation and Context
+
+<!--- Why is this change required? What problem does it solve? -->
+<!--- If it fixes an open issue, please link to the issue here. -->
+<!--- You can use the syntax `closes #100` if this solves the issue #100 -->
+
+- [ ] I have raised an issue to propose this change (required for new features and bug fixes)
+
+## Types of changes
+
+<!--- What types of changes does your code introduce? Put an `x` in all the boxes that apply: -->
+
+- [ ] Bug fix (non-breaking change which fixes an issue)
+- [ ] New feature (non-breaking change which adds functionality)
+- [ ] Breaking change (fix or feature that would cause existing functionality to change)
+- [ ] Documentation (update in the documentation)
+
+## Checklist
+
+<!--- Go over all the following points, and put an `x` in all the boxes that apply. -->
+<!--- If you're unsure about any of these, don't hesitate to ask. We're here to help! -->
+
+<!-- - [ ] I've read the [CONTRIBUTION](https://github.com/DLR-RM/stable-baselines3/blob/master/CONTRIBUTING.md) guide (**required**) -->
+
+- [ ] I have updated the changelog accordingly (**required**).
+- [ ] My change requires a change to the documentation.
+- [ ] I have updated the tests accordingly (_required for a bug fix or a new feature_).
+- [ ] I have updated the documentation accordingly.
+  <!-- - [ ] I have opened an associated PR on the [SB3-Contrib repository](https://github.com/Stable-Baselines-Team/stable-baselines3-contrib) (if necessary) -->
+  <!-- - [ ] I have opened an associated PR on the [RL-Zoo3 repository](https://github.com/DLR-RM/rl-baselines3-zoo) (if necessary) -->
+- [ ] I have reformatted the code and checked that formatting passes (**required**).
+- [ ] I have have fixed all issues found by `flake8` (**required**).
+- [ ] I have ensured that all `pytest` tests pass (**required**).
+- [ ] I have run `pytest` on a machine with a CUDA GPU and made sure all tests pass (**required**).
+- [ ] I have checked that the documentation builds (**required**).
+
+Note: We are using a maximum length of 88 characters per line
+
+<!--- This Template is an edited version of the one from https://github.com/DLR-RM/stable-baselines3/ -->