1.x unable to finish w3af dependency 3/3

[dhartford]

openssl/evp.h missing, later python.h missing, later libxml/xmlversion.h missing, need to add provisioning for libssl-dev and python-dev and libxml2-dev and libxslt1-dev.

recommend removal or review of provisioning/requirements, I had to remove role 'stouts.python' as during test run trying to get everything working, this got in the way.

[dhartford]

also need to add a call to:
pip install --upgrade pip