CVE-2018-18074: Upgrade requests to 2.19.1

Fixes CVE-2018-18074 [1]:

  The Requests package through 2.19.1 before 2018-09-14 for Python
  sends an HTTP Authorization header to an http URI upon receiving
  a same-hostname https-to-http redirect, which makes it easier for
  remote attackers to discover credentials by sniffing the network.

[1] https://nvd.nist.gov/vuln/detail/CVE-2018-18074

Change-Id: I064de6beb227e40ae4904e1bd23b297da9626f49
diff --git a/Pipfile.lock b/Pipfile.lock
index b1dcc2c..26f5298 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -18,10 +18,10 @@
     "default": {
         "certifi": {
             "hashes": [
-                "sha256:13e698f54293db9f89122b0581843a782ad0934a4fe0172d2a980ba77fc61bb7",
-                "sha256:9fa520c1bacfb634fa7af20a76bcbd3d5fb390481724c597da32c719a7dca4b0"
+                "sha256:339dc09518b07e2fa7eda5450740925974815557727d6bd35d319c1524a04a4c",
+                "sha256:6d58c986d22b038c8c0df30d639f23a3e6d172a05c3583e766f4c0b785c0986a"
             ],
-            "version": "==2018.4.16"
+            "version": "==2018.10.15"
         },
         "chardet": {
             "hashes": [
@@ -32,10 +32,10 @@
         },
         "idna": {
             "hashes": [
-                "sha256:2c6a5de3089009e3da7c5dde64a141dbc8551d5b7f6cf4ed7c2568d0cc520a8f",
-                "sha256:8c7309c718f94b3a625cb648ace320157ad16ff131ae0af362c9f21b80ef6ec4"
+                "sha256:156a6814fb5ac1fc6850fb002e0852d56c0c8d2531923a51032d1b70760e186e",
+                "sha256:684a38a6f903c1d71d6d5fac066b58d7768af4de2b832e426ec79c30daa94a16"
             ],
-            "version": "==2.6"
+            "version": "==2.7"
         },
         "jinja2": {
             "hashes": [
@@ -53,17 +53,17 @@
         },
         "pbr": {
             "hashes": [
-                "sha256:4f2b11d95917af76e936811be8361b2b19616e5ef3b55956a429ec7864378e0c",
-                "sha256:e0f23b61ec42473723b2fec2f33fb12558ff221ee551962f01dd4de9053c2055"
+                "sha256:8fc938b1123902f5610b06756a31b1e6febf0d105ae393695b0c9d4244ed2910",
+                "sha256:f20ec0abbf132471b68963bb34d9c78e603a5cf9e24473f14358e66551d47475"
             ],
-            "version": "==4.1.0"
+            "version": "==5.1.0"
         },
         "pygerrit2": {
             "hashes": [
-                "sha256:4a0e3e47c21b0c72b66a913db7f9605d50a2f82642a31980b459e0db570ad342"
+                "sha256:9c2676d947b10c41d0662ea74c5ed4ced1db735118658af5de0e0cd69db99444"
             ],
             "index": "pypi",
-            "version": "==2.0.6"
+            "version": "==2.0.7"
         },
         "python-gnupg": {
             "hashes": [
@@ -75,17 +75,17 @@
         },
         "requests": {
             "hashes": [
-                "sha256:6a1b267aa90cac58ac3a765d067950e7dbbf75b1da07e895d1f594193a40a38b",
-                "sha256:9c443e7324ba5b85070c4a818ade28bfabedf16ea10206da1132edaa6dda237e"
+                "sha256:63b52e3c866428a224f97cab011de738c36aec0185aa91cfacd418b5d58911d1",
+                "sha256:ec22d826a36ed72a7358ff3fe56cbd4ba69dd7a6718ffd450ff0e9df7a47ce6a"
             ],
-            "version": "==2.18.4"
+            "version": "==2.19.1"
         },
         "urllib3": {
             "hashes": [
-                "sha256:06330f386d6e4b195fbfc736b297f58c5a892e4440e54d294d7004e3a9bbea1b",
-                "sha256:cc44da8e1145637334317feebd728bd869a35285b93cbb4cca2577da7e62db4f"
+                "sha256:a68ac5e15e76e7e5dd2b8f94007233e01effe3e50e8daddf69acfd81cb686baf",
+                "sha256:b5725a0bd4ba422ab0e66e89e030c806576753ea3ee08554382c14e685d117b5"
             ],
-            "version": "==1.22"
+            "version": "==1.23"
         }
     },
     "develop": {