Scheduled monthly dependency update for February (#121)

* Update sphinx from 1.6.5 to 1.6.6

* Update msgpack-python from 0.4.8 to 0.5.1

* Update isort from 4.2.15 to 4.3.0

* Update pytest from 3.3.1 to 3.4.0

docs/requirements.txt

@@ -1,4 +1,4 @@
 docutils==0.14
 Pygments==2.2.0
-Sphinx==1.6.5
+Sphinx==1.6.6
 sphinxcontrib-websupport==1.0.1

requirements.txt

@@ -2,5 +2,5 @@
 -r docs/requirements.txt
 -r tests/requirements.txt
 
-msgpack-python==0.4.8
+msgpack-python==0.5.1
 ujson==1.35

tests/requirements.txt

@@ -1,10 +1,10 @@
 coverage==4.4.2
 flake8==3.5.0
-isort==4.2.15
+isort==4.3.0
 mypy==0.560
 pycodestyle==2.3.1
 pyflakes==1.6.0
-pytest==3.3.1
+pytest==3.4.0
 pytest-cov==2.5.1
 pytest-isort==0.1.0
 pytest-mock==1.6.3