[MRG] Templates (#181)

* Add a PR template

* move github contrib + code of conduct

* fix links

* add feature request template

* ask for gpu info

* address comments

* add gitter in README

Author: ayushkarnawat

CODE_OF_CONDUCT.md renamed to .github/CODE_OF_CONDUCT.md

@@ -1,27 +1,42 @@
 ---
 name: Bug report
 about: Create a report to help us improve POT
+title: ''
+labels: bug, help wanted
+assignees: ''
 
 ---
 
-**Describe the bug**
-A clear and concise description of what the bug is.
+## Describe the bug
+<!-- A clear and concise description of what the bug is. -->
 
-**To Reproduce**
+### To Reproduce
 Steps to reproduce the behavior:
-1 ...
+1. ...
 2. 
 
-**Expected behavior**
-A clear and concise description of what you expected to happen.
+<!-- If you have error messages or stack traces, please provide it here as well -->
 
-**Screenshots**
-If applicable, add screenshots to help explain your problem.
+#### Screenshots
+<!-- If applicable, add screenshots to help explain your problem. -->
 
-**Desktop (please complete the following information):**
- - OS: [e.g. MacOSX, Windows, Ubuntu]
- - Python version [2.7,3.6]
-- How was POT installed [source, pip, conda]
+#### Code sample
+<!-- Ideally attach a minimal code sample to reproduce the decried issue. 
+Minimal means having the shortest code but still preserving the bug. -->
+
+### Expected behavior
+<!-- A clear and concise description of what you expected to happen. -->
+
+
+### Environment (please complete the following information):
+- OS (e.g. MacOS, Windows, Linux):
+- Python version:
+- How was POT installed (source, `pip`, `conda`):
+- Build command you used (if compiling from source):
+- Only for GPU related bugs:
+    - CUDA version:
+    - GPU models and configuration:
+    - Any other relevant information:
 
 Output of the following code snippet:
 ```python
@@ -32,5 +47,5 @@ import scipy; print("SciPy", scipy.__version__)
 import ot; print("POT", ot.__version__)
 ```
 
-**Additional context**
-Add any other context about the problem here.
+### Additional context
+<!-- Add any other context about the problem here. -->

CONTRIBUTING.md renamed to .github/CONTRIBUTING.md

@@ -0,0 +1,23 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: enhancement, feature request
+assignees: ''
+
+---
+
+## 🚀 Feature
+<!-- A clear and concise description of the feature proposal -->
+
+### Motivation
+<!-- Please outline the motivation for the proposal. Is your feature request related to a problem? e.g., I'm always frustrated when [...]. If this is related to another GitHub issue, please link here too -->
+
+### Pitch
+<!-- A clear and concise description of what you want to happen. -->
+
+### Alternatives
+<!-- A clear and concise description of any alternative solutions or features you've considered, if any. -->
+
+### Additional context
+<!-- Add any other context or screenshots about the feature request here. -->

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,28 @@
+## Types of changes
+<!--- What types of changes does your code introduce? Put an `x` in all the boxes that apply: -->
+
+- [ ] Docs change / refactoring / dependency upgrade
+- [ ] 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)
+
+
+## Motivation and context / Related issue
+<!--- Why is this change required? What problem does it solve? -->
+<!--- Please link to an existing issue here if one exists. -->
+<!--- (we recommend to have an existing issue for each pull request) -->
+
+
+## How has this been tested (if it applies)
+<!--- Please describe here how your modifications have been tested. -->
+
+
+## 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! -->
+
+- [ ] The documentation is up-to-date with the changes I made.
+- [ ] I have read the [**CONTRIBUTING**](CONTRIBUTING.md) document.
+- [ ] All tests passed, and additional code has been covered with new tests.
+
+<!--- In any case, don't hesitate to join and ask questions if you need on slack (https://pot-toolbox.slack.com/), gitter (https://gitter.im/PythonOT/community), or the mailing list (https://mail.python.org/mm3/mailman3/lists/pot.python.org/). -->

.github/ISSUE_TEMPLATE/feature_request.md

@@ -190,17 +190,17 @@ This toolbox benefit a lot from open source research and we would like to thank
 
 ## Contributions and code of conduct
 
-Every contribution is welcome and should respect the [contribution guidelines](CONTRIBUTING.md). Each member of the project is expected to follow the [code of conduct](CODE_OF_CONDUCT.md).
+Every contribution is welcome and should respect the [contribution guidelines](.github/CONTRIBUTING.md). Each member of the project is expected to follow the [code of conduct](.github/CODE_OF_CONDUCT.md).
 
 ## Support
 
 You can ask questions and join the development discussion:
 
-* On the [POT Slack channel](https://pot-toolbox.slack.com)
+* On the POT [slack channel](https://pot-toolbox.slack.com)
+* On the POT [gitter channel](https://gitter.im/PythonOT/community)
 * On the POT [mailing list](https://mail.python.org/mm3/mailman3/lists/pot.python.org/)
 
-
-You can also post bug reports and feature requests in Github issues. Make sure to read our [guidelines](CONTRIBUTING.md) first.
+You can also post bug reports and feature requests in Github issues. Make sure to read our [guidelines](.github/CONTRIBUTING.md) first.
 
 ## References