d/control: Add missing dependency

debian/control

@@ -6,6 +6,7 @@ Build-Depends: debhelper (>= 9),
                dh-python (>= 2),
                python3 (>= 3.5) | python3-pyblake2,
                python3-all,
+               python3-click,
                python3-nose,
                python3-setuptools,
                python3-vcversioner

requirements.txt

@@ -2,3 +2,4 @@
 # should match https://pypi.python.org/pypi names. For the full spec or
 # dependency lines, see https://pip.readthedocs.org/en/1.1/requirements.html
 vcversioner
+Click