Updated url, version, and sha256 references

1. Updated homepage, url, and head to refer to GitHub rather than coin-or.org
2. Updated version reference to most recent (0.60.3)
3. Updated sha256 for appropriate version (pending)

Changes related to the issue discussed at coin-or/CoinUtils#151

cgl.rb

@@ -2,7 +2,7 @@ class Cgl < Formula
   desc "Cut-generation library"
   homepage "https://github.com/coin-or/Cgl"
   url "https://github.com/coin-or/Cgl/archive/releases/0.60.3.tar.gz"
-  sha256 "6b823a3fab554774018ec636f21f73ac7edd439b995dc0897a187dd657b23f18"
+  sha256 ""
   head "https://github.com/coin-or/Cgl/tree/releases/0.60.3/Cgl"
   revision 1