Update the ReadMe

Author: mdmintz

README.md

@@ -88,24 +88,22 @@ cd SeleniumBase
 
 If you're installing SeleniumBase from a cloned copy on your machine, use:
 ```
-pip install -r requirements.txt
+pip install -U -r requirements.txt
 
 python setup.py develop
 ```
 
 If you're installing SeleniumBase from the [Python Package Index](https://pypi.python.org/pypi/seleniumbase), use:
 ```bash
-pip install seleniumbase
+pip install -U seleniumbase
 ```
 
 If you're installing SeleniumBase directly from GitHub, use:
 ```bash
-pip install -e git+https://github.com/seleniumbase/SeleniumBase.git@master#egg=seleniumbase
+pip install -U -e git+https://github.com/seleniumbase/SeleniumBase.git@master#egg=seleniumbase
 ```
 
-(If you already have an older version installed, you may want to add ``--upgrade`` to your ``pip`` command to update existing Python packages. If you're not using a virtual environment, you may need to add ``--user`` to your ``pip`` command if you're getting errors during installation.)
-
-(If you want to use Python 3.x instead of Python 2.7, use ``pip3`` in place of ``pip`` and ``python3`` in place of ``python``.)
+(If you encounter permission errors during installation while not using a virtual environment, you may need to add ``--user`` to your ``pip`` command.)
 
 
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