add autopep8 to Contributions guide (#852)

* add autopep8 to Contrib.

* simplify cmd

* update GH templates

* add pytest-flake8

* update GH template

.github/CONTRIBUTING.md

@@ -51,3 +51,7 @@ A lot of good work has already been done in project mechanics (requirements.txt,
 ## Coding Styleguide
 1. Test the code with flake8.
 2. Use f-strings.
+3. run locally PEP8 fixes:
+    ```
+    autopep8 -v -r --max-line-length 120 --in-place .
+    ```

.github/ISSUE_TEMPLATE/bug_report.md

@@ -2,14 +2,16 @@
 name: Bug report
 about: Create a report to help us improve
 title: ''
-labels: bug
+labels: bug, help wanted
 assignees: ''
 
 ---
 
+<!-- 
 ### Common bugs:
 1. Tensorboard not showing in Jupyter-notebook see [issue 79](https://github.com/PyTorchLightning/pytorch-lightning/issues/79).    
 2. PyTorch 1.1.0 vs 1.2.0 support [see FAQ](https://github.com/PyTorchLightning/pytorch-lightning#faq)    
+-->
 
 ## 🐛 Bug
 

.github/ISSUE_TEMPLATE/documentation.md

@@ -2,7 +2,7 @@
 name: Typos and doc fixes
 about: Typos and doc fixes
 title: ''
-labels: typo
+labels: typo, documentation
 assignees: ''
 
 ---