Update pytest-html from 1.14.2 to 1.15.0 (#2547)

requirements/dev.txt

@@ -84,7 +84,9 @@ pytest-django==3.1.2 --hash=sha256:00995c2999b884a38ae9cd30a8c00ed32b3d38c104125
 selenium==3.4.3 \
     --hash=sha256:9e4885e7c72e20126b22ce5fc5981bbedd80bff99474c0757f62d5e68e1f17ac \
     --hash=sha256:0c09f437f4f6754c0543d79bae4e58b8fd40b3d7cd10889eca66dd1c7af24c63
-pytest-html==1.14.2 --hash=sha256:899d59d3e70f141ebf93b25b31e9d7c0a18469259cec3edaa3686f1d85b06c13
+pytest-html==1.15.0 \
+    --hash=sha256:aa1cedf68c60fef86affea43a1754e05bd4672c5f508ac39206cde05e1c78fcc \
+    --hash=sha256:02f9f31703b75ae9d40c4c473638d213eba24e3c49e842e3c67510cb6f493c44
 pytest-metadata==1.5.0 \
     --hash=sha256:d5788ced96426bf5ac890a7684ec24480782fda932cbdf9dbb073a4a2980770b \
     --hash=sha256:f962d1a2ecb57162a3067ba41958e726ed6eb017f69648cb9439e7635f841bc8