Merge pull request #382 from tsloughter/upgrade_relx

upgrade relx dep to latest mustache branch commit

rebar.lock

@@ -1,10 +1,10 @@
 [{<<"rebar_vsn_plugin">>,
   {git,"https://github.com/erlware/rebar_vsn_plugin.git",
        {ref,"fd40c960c7912193631d948fe962e1162a8d1334"}},
-  1},
+  2},
  {<<"relx">>,
   {git,"https://github.com/tsloughter/relx.git",
-       {ref,"732ad5a3f902a07972460731504ca7e085b80ae5"}},
+       {ref,"6e0d048d3840464539deddd9d5b53e9f421edee4"}},
   0},
  {<<"providers">>,
   {git,"https://github.com/tsloughter/providers.git",