Upgrade python requests + dependencies (#337)

requirements/build.txt

@@ -178,20 +178,20 @@ django-configurations==2.0 \
 django-cors-headers==2.1.0 \
     --hash=sha256:4e02be61ffaaab5917f1fd7cc3c305c4fb7ccd0156a649c96f49bc0a09c5f572 \
     --hash=sha256:451bc37a514792c2b46c52362368f7985985933ecdbf1a85f82652579a5cbe01
-requests==2.18.3 \
-    --hash=sha256:b62be4ec5999c24d10c98d248a136e7db20ca6616a2b65060cd9399417331e8a \
-    --hash=sha256:fb68a7baef4965c12d9cd67c0f5a46e6e28be3d8c7b6910c758fbcc99880b518
+requests==2.20.1 \
+    --hash=sha256:65b3a120e4329e33c9889db89c80976c5272f56ea92d3e74da8a463992e3ff54 \
+    --hash=sha256:ea881206e59f41dbd0bd445437d792e43906703fff75ca8ff43ccdb11f33f263
 
 # required by requests
-certifi==2017.7.27.1 \
-    --hash=sha256:54a07c09c586b0e4c619f02a5e94e36619da8e2b053e20f594348c0611803704 \
-    --hash=sha256:40523d2efb60523e113b44602298f0960e900388cf3bb6043f645cf57ea9e3f5
+certifi==2018.8.13 \
+    --hash=sha256:b6e8b28b2b7e771a41ecdd12d4d43262ecab52adebbafa42c77d6b57fb6ad3a4 \
+    --hash=sha256:4c1d68a1408dd090d2f3a869aa94c3947cc1d967821d1ed303208c9f41f0f2f4
 chardet==3.0.4 \
-      --hash=sha256:fc323ffcaeaed0e0a02bf4d117757b98aed530d9ed4531e3e15460124c106691 \
-      --hash=sha256:84ab92ed1c4d4f16916e05906b6b75a6c0fb5db821cc65e70cbd64a3e2a5eaae
-idna==2.6 \
-    --hash=sha256:8c7309c718f94b3a625cb648ace320157ad16ff131ae0af362c9f21b80ef6ec4 \
-    --hash=sha256:2c6a5de3089009e3da7c5dde64a141dbc8551d5b7f6cf4ed7c2568d0cc520a8f
+    --hash=sha256:fc323ffcaeaed0e0a02bf4d117757b98aed530d9ed4531e3e15460124c106691 \
+    --hash=sha256:84ab92ed1c4d4f16916e05906b6b75a6c0fb5db821cc65e70cbd64a3e2a5eaae
+idna==2.7 \
+    --hash=sha256:156a6814fb5ac1fc6850fb002e0852d56c0c8d2531923a51032d1b70760e186e \
+    --hash=sha256:684a38a6f903c1d71d6d5fac066b58d7768af4de2b832e426ec79c30daa94a16
 urllib3==1.22 \
     --hash=sha256:06330f386d6e4b195fbfc736b297f58c5a892e4440e54d294d7004e3a9bbea1b \
     --hash=sha256:cc44da8e1145637334317feebd728bd869a35285b93cbb4cca2577da7e62db4f