Update sphinx from 1.8.2 to 1.8.3

requirements/docs.txt

@@ -9,9 +9,9 @@ Pygments==2.3.1 \
     --hash=sha256:e8218dd399a61674745138520d0d4cf2621d7e032439341bc3f647bff125818d \
     --hash=sha256:5ffada19f6203563680669ee7f53b64dabbeb100eb51b61996085e99c03b284a
 # Sphinx is required by sphinxcontrib-httpdomain
-Sphinx==1.8.2 \
-    --hash=sha256:b348790776490894e0424101af9c8413f2a86831524bd55c5f379d3e3e12ca64 \
-    --hash=sha256:120732cbddb1b2364471c3d9f8bfd4b0c5b550862f99a65736c77f970b142aea
+Sphinx==1.8.3 \
+    --hash=sha256:429e3172466df289f0f742471d7e30ba3ee11f3b5aecd9a840480d03f14bcfe5 \
+    --hash=sha256:c4cb17ba44acffae3d3209646b6baec1e215cad3065e852c68cc569d4df1b9f8
 # alabaster is required by Sphinx
 alabaster==0.7.12 \
     --hash=sha256:446438bdcca0e05bd45ea2de1668c1d9b032e1a9154c2c259092d77031ddd359 \