Have install depend on the CLI (whenever that gets successfully packaged).

debian/control

@@ -11,6 +11,6 @@ Standards-Version: 3.9.3
 
 Package: writeas-gtk
 Architecture: any
-Depends: ${misc:Depends}, ${shlibs:Depends}
+Depends: ${misc:Depends}, ${shlibs:Depends}, writeas-cli
 Recommends: fonts-open-sans, fonts-hack
 Description: A distraction free and private writing tool, with builtin publishing.