-r requirements.txt
coverage==4.4.2
factory-boy==2.9.2
faker==0.8.8
flake8==3.5.0
mccabe==0.6.1
mock==2.0.0
pbr==3.1.1
pycodestyle==2.3.1
pyflakes==1.6.0
python-dateutil==2.6.1
selenium==3.8.1
six==1.11.0
text-unidecode==1.1
whoosh==2.7.4

-r requirements.txt
coverage==4.4.2
factory-boy==2.9.2
faker==0.8.8
flake8==3.5.0
mccabe==0.6.1
mock==2.0.0
pbr==3.1.1
pycodestyle==2.3.1
pyflakes==1.6.0
python-dateutil==2.6.1
selenium==3.8.1
six==1.11.0
text-unidecode==1.1
whoosh==2.7.4
lxml==4.2.4

Add lxml to test requirements
Add lxml to test requirements