Bump version to 1.18.7

debian/changelog

@@ -1,3 +1,9 @@
+dpkg (1.18.7) UNRELEASED; urgency=medium
+
+  *
+
+ -- Guillem Jover <guillem@debian.org>  Tue, 03 May 2016 21:07:19 +0200
+
 dpkg (1.18.6) unstable; urgency=medium
 
   [ Guillem Jover ]