handle ports race condition by returning 3000

fixes #40

This is a very simple to fix to the problem with ports where it
will occaisonally throw an error:

- hoodiehq-archive/node-ports#4

The fix is to catch the error and use port 3000.  Not great, but should
handle some cases where this was a problem.

An alternate fix to try would be to try fetching the port again, probably
in a loop (with some limit), in hopes of getting a value from ports.

.gitignore

@@ -1,3 +1,4 @@
 node_modules
 tmp
 npm-debug.log
+.vscode

lib-src/cfenv.coffee

@@ -174,7 +174,10 @@ getPort = (appEnv) ->
   unless portString?
     return 3000 unless appEnv.name?
 
-    portString = "#{ports.getPort appEnv.name}"
+    try
+      portString = "#{ports.getPort appEnv.name}"
+    catch e
+      portString = '3000'
 
   port = parseInt portString, 10
   throwError "invalid PORT value: /#{portString}/" if isNaN port