switch to https for getopt so github account isn't needed

rebar.config

@@ -33,7 +33,7 @@
         {relx, "",
          {git, "https://github.com/erlware/relx.git",
           {branch, "master"}}},
-        {getopt, "", {git, "git@github.com:jcomellas/getopt.git", {branch, "master"}}}]}.
+        {getopt, "", {git, "https://github.com/jcomellas/getopt.git", {branch, "master"}}}]}.
 
 {erlydtl_opts, [{doc_root, "priv/templates"},
                 {compiler_options, [report, return, debug_info]}]}.