Resolve "python pip version errors"

Closes #229 (closed)

requirements.txt

 Django==1.10.7
+django_otp==0.4.3
 gunicorn==19.6.0
 Pillow==3.4.2
 psycopg2==2.6.2
@@ -11,7 +12,8 @@ django-two-factor-auth==1.6.1
 nexmo
 django-excel==0.0.9
 pyexcel-xls==0.5.0
-pyexcel==0.5.3
+pyexcel==0.5.8
+pyexcel-io==0.5.8
 pycurl==7.43.0
 django-stronghold==0.2.9