removed makefile and updated readme

Author: Kareem Zidane

Makefile

@@ -4,19 +4,11 @@
 
 Supports Python 2 and Python 3.
 
-## Development
-
-Requires [Docker Engine](https://docs.docker.com/engine/installation/).
-
-    make bash
-    make deb # builds .deb
-
 ## Installation
 
-1. Download the latest release per https://github.com/cs50/python-cs50/releases
-1. Extract `python-cs50-*`
-1. `cd python-cs50-*`
-1. `make install`
+```
+pip install cs50
+```
 
 ## Usage
 
@@ -31,8 +23,6 @@ Requires [Docker Engine](https://docs.docker.com/engine/installation/).
     s = cs50.get_string();
 
 ## TODO
-
-* Add install target to Makefile.
 * Conditionally install for Python 2 and/or Python 3.
 * Add targets for `pacman`, `rpm`.
 * Add tests.