[requires.io] dependency update

requires · requires · commit 440ddad3694f · 2017-08-17T18:30:13.000-05:00
diff --git a/test_requirements.txt b/test_requirements.txt
@@ -1,4 +1,4 @@
 pytest==3.2.1
 pytest-cov==2.5.1
 pytest-xdist==1.19.1
-hypothesis==3.18.3
+hypothesis==3.18.4
