Update requests from 2.17.3 to 2.18.1 (#2560)

requirements/common.txt

@@ -115,9 +115,9 @@ openapi-codec==1.3.1 \
 itypes==1.1.0 --hash=sha256:c6e77bb9fd68a4bfeb9d958fea421802282451a25bac4913ec94db82a899c073
 uritemplate==3.0.0 --hash=sha256:1b9c467a940ce9fb9f50df819e8ddd14696f89b9a8cc87ac77952ba416e0a8fd
 
-requests==2.17.3 \
-    --hash=sha256:baf701b4a9d4cbe40169e8ab77816f7abadbad502ba459c30f7a2bc138e4d612 \
-    --hash=sha256:8d29f97ed1541709b57caddb77bb20592411d7ca10ec4f03275f49ee8456e225
+requests==2.18.1 \
+    --hash=sha256:6afd3371c1f4c1970497cdcace5c5ecbbe58267bf05ca1abd93d99d170803ab7 \
+    --hash=sha256:c6f3bdf4a4323ac7b45d01e04a6f6c20e32a052cd04de81e05103abc049ad9b9
 
 # Required by django.contrib.migrations
 sqlparse==0.2.3 \