tmp dir setting was being ignored in TmpStore

Author: inversion

lib/store/tmp.js

@@ -46,7 +46,7 @@ util.inherits(TmpStore, Store);
 Store.mix(TmpStore, {
     generateTmpFileName: function () {
         this.seq += 1;
-        return this.prefix + this.seq + '.tmp';
+        return path.join(this.tmp, this.prefix + this.seq + '.tmp');
     },
 
     set: function (key, contents) {