[pkg] add python-docutils dependency to debian control

This dependency was missing in the in 0.1.0-1

debian/control

@@ -8,7 +8,7 @@
 
 Package: cubicweb-card
 Architecture: all
-Depends: cubicweb-common (>= 3.2.0)
+Depends: cubicweb-common (>= 3.2.0), python-docutils
 Description: card component for the CubicWeb framework
  This CubicWeb component models cards that are like wiki pages.
  Cards have a title, an abstract and some textual content as text, rest or html.