change .outputErrors to false for "test" env only

good to know in prod ;)

docs/api.md

@@ -42,7 +42,7 @@ http.createServer(app.callback()).listen(3001);
   - `app.proxy` when true proxy header fields will be trusted
   - `app.subdomainOffset` offset of `.subdomains` to ignore [2]
   - `app.jsonSpaces` default JSON response spaces [2]
-  - `app.outputErrors` output err.stack to stderr [true in "development"]
+  - `app.outputErrors` output err.stack to stderr [false in "test" environment]
 
 ### app.listen(...)
 

lib/application.js

@@ -33,7 +33,7 @@ exports = module.exports = Application;
 function Application() {
   if (!(this instanceof Application)) return new Application;
   this.env = process.env.NODE_ENV || 'development';
-  this.outputErrors = 'development' == this.env;
+  this.outputErrors = 'test' != this.env;
   this.subdomainOffset = 2;
   this.poweredBy = true;
   this.jsonSpaces = 2;