Rolled version number to 1.6.0

Author: Edward J M Easton

setup.py

@@ -75,7 +75,7 @@ def run_tests(self):
 
 setup(
     name="arctic",
-    version="1.5.0",
+    version="1.6.0",
     author="Man AHL Technology",
     author_email="[email protected]",
     description=("AHL Research Versioned TimeSeries and Tick store"),