Merge pull request #67 from N-BodyPhysicsSimulator/codex/update-installation-process-and-readme

Update Makefile install target

Author: StephanMeijer

Makefile

@@ -22,7 +22,7 @@ codecov:
 install-requirements: install-requirements-app install-requirements-dev
 
 install-requirements-app:
-	pip install -r requirements.txt
+        python3 -m pip install .
 
 install-requirements-dev:
 	pip install -r requirements-dev.txt

README.md

@@ -30,8 +30,11 @@ Not tested on `Mac OS X`/`macOS` or `Microsoft Windows`.
 
 #### Installation from source
 
-1. Run `make install-requirements-app`
-2. Run tests and make sure there aren't any failing tests.
+1. Run `make install-requirements-app` to install the package and its
+   dependencies.
+2. (Optional) run `make install-requirements-dev` for development
+   requirements.
+3. Run tests and make sure there aren't any failing tests.
 
 #### Run tests