fix: Install Bleach dependencies in correct order

A more elegant solution to the original problem has been found. It seems that the Bleach package now installs its dependencies in the wrong order, which then breaks the pip command itself. The dependencies are now installed before Bleach to resolve this issue.

Author: SteveWooding

vagrant/pg_config.sh

@@ -1,8 +1,10 @@
 apt-get -qqy update
 apt-get -qqy install postgresql python-psycopg2
 apt-get -qqy install python-flask python-sqlalchemy
-wget https://bootstrap.pypa.io/get-pip.py
-python ./get-pip.py
+apt-get -qqy install python-pip
+pip install packaging
+pip install appdirs
+pip install -U six
 pip install bleach
 pip install oauth2client
 pip install requests