Scheduled daily dependency update on saturday (#45)

* Update hypothesis from 3.44.26 to 3.45.1

* Pin filefinder2 to latest version 0.4.1

* Pin rosimport to latest version 0.2.1

* Pin pytest-xdist to latest version 1.22.0

* Pin numpy to latest version 1.14.0

requirements/python/tests.txt

@@ -1,9 +1,9 @@
 # latest version to validate behavior on pure python env
 pytest==3.4.0
-pytest-xdist  # for --boxed
-hypothesis==3.44.26
-numpy
+pytest-xdist==1.22.0  # for --boxed
+hypothesis==3.45.1
+numpy==1.14.0
 
 # These dependencies are python pkgs only and only for tests.
-filefinder2
-rosimport
+filefinder2==0.4.1
+rosimport==0.2.1