Update pytest-metadata to 1.4.0 (#109)

* Update pytest-metadata from 1.3.0 to 1.4.0

* Update pytest-metadata from 1.3.0 to 1.4.0

requirements/py27-tests.txt

@@ -1,7 +1,7 @@
 mock==2.0.0
 mozlog==3.4
 pytest==3.0.7
-pytest-metadata==1.3.0
+pytest-metadata==1.4.0
 pytest-selenium==1.10.0
 pytest-xdist==1.16.0
 selenium==3.4.1

requirements/py36-tests.txt

@@ -1,6 +1,6 @@
 mock==2.0.0
 pytest==3.0.7
-pytest-metadata==1.3.0
+pytest-metadata==1.4.0
 pytest-selenium==1.10.0
 pytest-xdist==1.16.0
 selenium==3.4.1