Upgrade Django to 2.2.9 (#379)

requirements/build.txt

@@ -21,9 +21,8 @@ hashin==0.11.2 \
 argparse==1.4.0 \
     --hash=sha256:c31647edb69fd3d465a847ea3157d37bed1f95f19760b11a47aa91c04b666314 \
     --hash=sha256:62b089a55be1d8949cd2bc7e0df0bddb9e028faefc8c32038cc84862aefdd6e4
-Django==2.1.11 \
-    --hash=sha256:305b6c4fce9e03bb746e35780c2c4d52f29ea1669f15633cfd41bc8821c74c76 \
-    --hash=sha256:1a41831eace203fd1939edf899e07d7abd12ce9bafc3d9a5a63a24a8d1d12bd5
+Django==2.2.9 \
+    --hash=sha256:687c37153486cf26c3fdcbdd177ef16de38dc3463f094b5f9c9955d91f277b14
 sqlparse==0.3.0 \
     --hash=sha256:40afe6b8d4b1117e7dff5504d7a8ce07d9a1b15aeeade8a2d10f130a834f8177 \
     --hash=sha256:7c3dca29c022744e95b547e867cee89f4fce4373f3549ccd8797d8eb52cdb873