Update CONTRIBUTING.md file

Fix #11

Author: absci

CONTRIBUTING.md

@@ -2,6 +2,39 @@
 
 ## How to contribute
 
+### Run unit tests
+After changes made to the project, it's a good idea to run the unit tests before making a pull request. 
+
+
+1. **Run SQL Server**  
+   Make sure you have SQL Server running in your local machine. 
+   Download and install SQL Server [here](https://www.microsoft.com/en-us/sql-server/sql-server-downloads), or you could use docker. Change `testapp/settings.py` to match your SQL Server login username and password.  
+   
+   ```
+   docker run -e 'ACCEPT_EULA=Y' -e 'SA_PASSWORD=MyPassword42' -p 1433:1433 -d mcr.microsoft.com/mssql/server:2019-latest
+   ```
+2. **Clone Django**   
+   In `mssql-django` folder. 
+   ```
+   # Install your local mssql-django
+   pip install -e .
+
+   # The unit test suite are in `Django` folder, so we need to clone it
+   git clone https://github.com/django/django.git --depth 1
+   ```
+   
+3. **Install Tox**  
+   ```
+   # we use `tox` to run tests and install dependencies
+   pip install tox
+   ``` 
+4. **Run Tox**  
+   ```
+   # eg. run django 3.1 tests with Python 3.7
+   tox -e py37-django31
+   ```
+
+---
 This project welcomes contributions and suggestions.  Most contributions require you to agree to a
 Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us
 the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.

README.md

@@ -233,6 +233,8 @@ The following features and additions are planned:
 
 ## Contributing
 
+More details on contributing can be found [Here](CONTRIBUTING.md).
+
 This project welcomes contributions and suggestions.  Most contributions require you to agree to a
 Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us
 the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.