Add post "Setting Up a Development Environment"

Signed-off-by: Don Naegely <naegelyd@gmail.com>
I had to read this sentence a few times to understand why the `--no-deps` flag was being used. Maybe it would be clearer as something like the below, assuming I'm understanding correctly:

...and the `--no-deps` flag to avoid installing the Avocado and Serrano requirements, which might overwrite packages already installed as Harvest OpenMRS requirements. Of course, if you wish to update the Avocado and/or Serrano requirements, you can choose not to include the `--no-deps` flag.