Bump cryptography from 2.3.1 to 2.4.2 (#1541)

Bumps [cryptography](https://github.com/pyca/cryptography) from 2.3.1 to 2.4.2.
- [Release notes](https://github.com/pyca/cryptography/releases)
- [Changelog](https://github.com/pyca/cryptography/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pyca/cryptography/compare/2.3.1...2.4.2)

Signed-off-by: dependabot[bot] <support@dependabot.com>

requirements/build.txt

@@ -87,26 +87,26 @@ django-constance==2.3.1 \
     --hash=sha256:a49735063b2c30015d2e52a90609ea9798da722ed070f091de51714758a5d018
 django-npm==1.0.0 \
     --hash=sha256:2e6bba65e728fa18b9db3c8dc0d4490b70cb7f43bacf60eb3654d7dcb6424272
-cryptography==2.3.1 \
-    --hash=sha256:17db09db9d7c5de130023657be42689d1a5f60502a14f6f745f6f65a6b8195c0 \
-    --hash=sha256:e4aecdd9d5a3d06c337894c9a6e2961898d3f64fe54ca920a72234a3de0f9cb3 \
-    --hash=sha256:10b48e848e1edb93c1d3b797c83c72b4c387ab0eb4330aaa26da8049a6cbede0 \
-    --hash=sha256:2cbaa03ac677db6c821dac3f4cdfd1461a32d0615847eedbb0df54bb7802e1f7 \
-    --hash=sha256:31db8febfc768e4b4bd826750a70c79c99ea423f4697d1dab764eb9f9f849519 \
-    --hash=sha256:7e3b4aecc4040928efa8a7cdaf074e868af32c58ffc9bb77e7bf2c1a16783286 \
-    --hash=sha256:02602e1672b62e803e08617ec286041cc453e8d43f093a5f4162095506bc0beb \
-    --hash=sha256:dc2d3f3b1548f4d11786616cf0f4415e25b0fbecb8a1d2cd8c07568f13fdde38 \
-    --hash=sha256:76936ec70a9b72eb8c58314c38c55a0336a2b36de0c7ee8fb874a4547cadbd39 \
-    --hash=sha256:8229ceb79a1792823d87779959184a1bf95768e9248c93ae9f97c7a2f60376a1 \
-    --hash=sha256:8a19e9f2fe69f6a44a5c156968d9fc8df56d09798d0c6a34ccc373bb186cee86 \
-    --hash=sha256:8168bcb08403ef144ff1fb880d416f49e2728101d02aaadfe9645883222c0aa5 \
-    --hash=sha256:6a88d9004310a198c474d8a822ee96a6dd6c01efe66facdf17cb692512ae5bc0 \
-    --hash=sha256:be495b8ec5a939a7605274b6e59fbc35e76f5ad814ae010eb679529671c9e119 \
-    --hash=sha256:4a510d268e55e2e067715d728e4ca6cd26a8e9f1f3d174faf88e6f2cb6b6c395 \
-    --hash=sha256:227da3a896df1106b1a69b1e319dce218fa04395e8cc78be7e31ca94c21254bc \
-    --hash=sha256:e79ab4485b99eacb2166f3212218dd858258f374855e1568f728462b0e6ee0d9 \
-    --hash=sha256:f995d3667301e1754c57b04e0bae6f0fa9d710697a9f8d6712e8cca02550910f \
-    --hash=sha256:8d10113ca826a4c29d5b85b2c4e045ffa8bad74fb525ee0eceb1d38d4c70dfd6
+cryptography==2.4.2 \
+    --hash=sha256:0ff4a3d6ea86aa0c9e06e92a9f986de7ee8231f36c4da1b31c61a7e692ef3378 \
+    --hash=sha256:63b064a074f8dc61be81449796e2c3f4e308b6eba04a241a5c9f2d05e882c681 \
+    --hash=sha256:b4fc04326b2d259ddd59ed8ea20405d2e695486ab4c5e1e49b025c484845206e \
+    --hash=sha256:0eb83a24c650a36f68e31a6d0a70f7ad9c358fa2506dc7b683398b92e354a038 \
+    --hash=sha256:af12dfc9874ac27ebe57fc28c8df0e8afa11f2a1025566476b0d50cdb8884f70 \
+    --hash=sha256:5ecaf9e7db3ca582c6de6229525d35db8a4e59dc3e8a40a331674ed90e658cbf \
+    --hash=sha256:3cdc5f7ca057b2214ce4569e01b0f368b3de9d8ee01887557755ccd1c15d9427 \
+    --hash=sha256:21e63dd20f5e5455e8b34179ac43d95b3fb1ffa54d071fd2ed5d67da82cfe6dc \
+    --hash=sha256:8908f1db90be48b060888e9c96a0dee9d842765ce9594ff6a23da61086116bb6 \
+    --hash=sha256:70596e90398574b77929cd87e1ac6e43edd0e29ba01e1365fed9c26bde295aa5 \
+    --hash=sha256:471a097076a7c4ab85561d7fa9a1239bd2ae1f9fd0047520f13d8b340bf3210b \
+    --hash=sha256:70c2b04e905d3f72e2ba12c58a590817128dfca08949173faa19a42c824efa0b \
+    --hash=sha256:6afe324dfe6074822ccd56d80420df750e19ac30a4e56c925746c735cf22ae8b \
+    --hash=sha256:da5b5dda4aa0d5e2b758cc8dfc67f8d4212e88ea9caad5f61ba132f948bab859 \
+    --hash=sha256:1699f3e916981df32afdd014fb3164db28cdb61c757029f502cb0a8c29b2fdb3 \
+    --hash=sha256:2454ada8209bbde97065453a6ca488884bbb263e623d35ba183821317a58b46f \
+    --hash=sha256:1b1f136d74f411f587b07c076149c4436a169dc19532e587460d9ced24adcc13 \
+    --hash=sha256:418e7a5ec02a7056d3a4f0c0e7ea81df374205f25f4720bb0e84189aa5fd2515 \
+    --hash=sha256:05a6052c6a9f17ff78ba78f8e6eb1d777d25db3b763343a1ae89a7a8670386dd
 cffi==1.11.5 \
     --hash=sha256:1b0493c091a1898f1136e3f4f991a784437fac3673780ff9de3bcf46c80b6b50 \
     --hash=sha256:87f37fe5130574ff76c17cab61e7d2538a16f843bb7bca8ebbc4b12de3078596 \