Update sphinx from 1.7.8 to 1.7.9

requirements/docs.txt

@@ -9,9 +9,9 @@ Pygments==2.2.0 \
     --hash=sha256:78f3f434bcc5d6ee09020f92ba487f95ba50f1e3ef83ae96b9d5ffa1bab25c5d \
     --hash=sha256:dbae1046def0efb574852fab9e90209b23f556367b5a320c0bcb871c77c3e8cc
 # Sphinx is required by sphinxcontrib-httpdomain
-Sphinx==1.7.8 \
-    --hash=sha256:d719de667218d763e8fd144b7fcfeefd8d434a6201f76bf9f0f0c1fa6f47fcdb \
-    --hash=sha256:a07050845cc9a2f4026a6035cc8ed795a5ce7be6528bbc82032385c10807dfe7
+Sphinx==1.7.9 \
+    --hash=sha256:a602513f385f1d5785ff1ca420d9c7eb1a1b63381733b2f0ea8188a391314a86 \
+    --hash=sha256:217a7705adcb573da5bbe1e0f5cab4fa0bd89fd9342c9159121746f593c2d5a4
 # alabaster is required by Sphinx
 alabaster==0.7.11 \
     --hash=sha256:674bb3bab080f598371f4443c5008cbfeb1a5e622dd312395d2d82af2c54c456 \