deps: update pytest from 4.3.1 to 4.4.0

Update pytest from 4.3.1 to 4.4.0 (#29)
2019-04-02 11:46:05 +02:00 · 2019-04-02 11:46:05 +02:00 · e695956a0e
--- a/requirements.txt
+++ b/requirements.txt
@ -1,4 +1,4 @@
 mock==2.0.0
 pylint==1.9.3 # pyup: ignore
-pytest==4.3.1
+pytest==4.4.0
 snapshottest==0.5.0