Apply suggestion to docs/installation_instructions.md

docs/installation_instructions.md

@@ -47,7 +47,7 @@ guide][https://openappstack.net/contact.html).
 * A trusted machine to run the installer on (we call this the `provisioning
   machine`). All the commands listed in these instructions should be run on the
   provisioning machine, unless specified otherwise.
-  * You need Python 3 and Git installed (`apt install python3 git`)
+  * You need Python 3 with it's development files, Pip and Git installed (`apt install python3-pip python3-dev git`)
   * We recommend using a [python virtualenv](https://docs.python.org/3/tutorial/venv.html)
     to make sure we do not change any of your other projects. Install virtualenv
     by running `pip3 install --user venv` or `apt install python3-venv`