switch back to erlware relx repo

rebar.config

@@ -35,7 +35,7 @@
         {git, "https://github.com/tsloughter/providers.git",
          {branch, "master"}}},
        {relx, "",
-        {git, "https://github.com/tsloughter/relx.git",
+        {git, "https://github.com/erlware/relx.git",
          {branch, "master"}}},
        {getopt, "", {git, "https://github.com/jcomellas/getopt.git", {branch, "master"}}}]}.