adding pypi installation instructions

Author: mriehl

README.md

@@ -3,15 +3,8 @@ PythonVerbalExpressions
 
 ## Installation
 ```bash
-python setup.py install
+pip install VerbalExpressions
 ```
-
-Hopefully you will also be able to use
-```bash
-pip install verbalexpressions
-```
-in the near future.
-
 ## Usage
 ```python
 from verbalexpressions import VerEx
@@ -20,5 +13,6 @@ verbal_expression = VerEx()
 
 ## Developer setup : running the tests
 ```bash
+python setup.py develop
 python setup.py test
 ```