Update virtualenv from 16.7.2 to 16.7.4

pyup-bot · pyup-bot · commit 6696f2f551e3 · 2019-09-02T14:07:08.000-05:00
diff --git a/requirements/pip.txt b/requirements/pip.txt
@@ -1,7 +1,7 @@
 # Base packages
 pip==19.2.3
 appdirs==1.4.3
-virtualenv==16.7.2
+virtualenv==16.7.4
 
 django==1.11.23  # pyup: <1.12
 django-extensions==2.2.1
