Update requests from 2.18.3 to 2.18.4 (#2706)

requirements/common.txt

@@ -132,9 +132,9 @@ openapi-codec==1.3.2 \
 itypes==1.1.0 --hash=sha256:c6e77bb9fd68a4bfeb9d958fea421802282451a25bac4913ec94db82a899c073
 uritemplate==3.0.0 --hash=sha256:1b9c467a940ce9fb9f50df819e8ddd14696f89b9a8cc87ac77952ba416e0a8fd
 
-requests==2.18.3 \
-    --hash=sha256:b62be4ec5999c24d10c98d248a136e7db20ca6616a2b65060cd9399417331e8a \
-    --hash=sha256:fb68a7baef4965c12d9cd67c0f5a46e6e28be3d8c7b6910c758fbcc99880b518
+requests==2.18.4 \
+    --hash=sha256:6a1b267aa90cac58ac3a765d067950e7dbbf75b1da07e895d1f594193a40a38b \
+    --hash=sha256:9c443e7324ba5b85070c4a818ade28bfabedf16ea10206da1132edaa6dda237e
 
 # Required by django.contrib.migrations
 sqlparse==0.2.3 \