Adding dev-repo field

Author: David Pichardie

packages/sawja/sawja.1.5.8/opam

@@ -4,6 +4,7 @@ authors: "Sawja development team"
 homepage: "http://sawja.inria.fr"
 bug-reports: "sawja@inria.fr"
 license: "GPL V3"
+dev-repo: "git+https://github.com/javalib-team/sawja.git"
 build: [
   ["./configure.sh"]
   [make]