Add prepublish script so I stop forgetting to re-run dist before publishing

Author: ssenbud

package.json

@@ -21,9 +21,9 @@
     "url": "git://github.com/stacktracejs/stacktrace.js.git"
   },
   "dependencies": {
-    "error-stack-parser": "~1.2",
-    "stack-generator": "~1.0",
-    "stacktrace-gps": "~2.4"
+    "error-stack-parser": "^1.3.5",
+    "stack-generator": "^1.0.7",
+    "stacktrace-gps": "^2.4.1"
   },
   "devDependencies": {
     "colors": "^1.1.2",
@@ -66,6 +66,7 @@
     "dist/"
   ],
   "scripts": {
-    "test": "gulp test"
+    "test": "gulp test",
+    "prepublish": "gulp dist"
   }
 }