e2e: add profile for running offline tests

Tag tests that require internet access with '@online' and add a Cucumber
profile that skips those tests. This allows developers to easily run tests
on the bundle server in an offline or bandwidth-limited environment.

Signed-off-by: Victoria Dye <vdye@github.com>

Author: vdye

test/e2e/cucumber.js

@@ -18,6 +18,10 @@ module.exports = {
     ...common,
     tags: 'not @slow',
   },
+  offline: {
+    ...common,
+    tags: 'not @online',
+  },
   all: {
     ...common
   }

test/e2e/features/basic.feature

@@ -3,6 +3,7 @@ Feature: Basic bundle server usage
   Background: The bundle web server is running
     Given the bundle web server was started at port 8080
 
+  @online
   Scenario: A user can clone with a bundle URI pointing to the bundle server
     Given a remote repository 'https://github.com/vdye/asset-hash.git'
     Given the bundle server has been initialized with the remote repo

test/e2e/features/performance.feature

@@ -3,6 +3,7 @@ Feature: Bundle server performance
   Background: The bundle web server is running
     Given the bundle web server was started at port 8080
 
+  @online
   Scenario Outline: Comparing clone performance
     Given a remote repository '<repo>'
     Given the bundle server has been initialized with the remote repo