Use different mock version

Faustasm · Faustasm · commit 37a1d7ed2bdb · 2020-10-26T19:53:36.000+02:00
diff --git a/requirements-dev.txt b/requirements-dev.txt
@@ -1,7 +1,7 @@
 pytest==4.0.2
 attrs==19.1.0
 py==1.9.0
-mock==4.0.2
+mock==3.0.5
 responses==0.3.0
 safety==1.9.0
 
