extra checks for unreliable fs.watchFile()

Could not pull the request directly as the code didn't lint properly. Added make lint to the test command. Closes #13

Makefile

@@ -8,6 +8,7 @@ help:
 test:
 	@make setup
 	@make clean
+	@make lint
 	@mocha --reporter spec $(MOCHAFLAGS)
 
 # Lints the code

lib/sauce-connect-launcher.js

@@ -165,7 +165,11 @@ function run(options, callback) {
   // Watching file as directory watching does not work on
   // all File Systems http://nodejs.org/api/fs.html#fs_caveats
   watcher = fs.watchFile(readyfile, {persistent: false}, function () {
-    ready();
+    fs.exists(readyfile, function (exists) {
+      if (exists) {
+        ready();
+      }
+    });
   });
 
   watcher.on("error", callback);

package.json

@@ -17,7 +17,7 @@
     "url": "https://github.com/bermi/sauce-connect-launcher"
   },
   "scripts": {
-    "test": "mocha --reporter spec"
+    "test": "make test"
   },
   "dependencies": {
     "lodash": "~1.3.1",