Add integration tests

[alexanderdean]

The general idea for integration tests:

• Run them in Sauce Labs
• Run a node.js server as a mock Snowplow Collector
• Point the Snowplow JS Tracker to the mock Snowplow Collector
• Fire events from the Snowplow JS Tracker
• Verify the payload sent to the mock Snowplow Collector

[alexanderdean]

See also Simon Rumble (@shermozle)'s email thread for inspiration:

https://groups.google.com/forum/#!msg/snowplow-user/Jxmj6Kaj074/Cj1-hfA9ezEJ

[alexanderdean]

For further inspiration: http://viget.com/extend/testing-google-analytics-with-phantomjs

[alexanderdean]

Fred Blundun (@fblundun) - can you update this ticket with what you have tried and what is not working?

[fblundun]

Just installing Mountebank by adding the line

install:
 - npm install -g mountebank --production

to .travis.yml causes the error Fatal error: Unable to find local grunt.

(See the failing build and the commit which fixed it)

[alexanderdean]

Mountebank tests in our PHP Tracker: https://github.com/snowplow/snowplow-php-tracker/blob/master/.travis.yml

[fblundun]

There are a couple of practical problems using Mountebank:

• We don't know how to send an image in response to the tracker's GET requests, which prevents the tracker from sending more than one event
• In order to verify that requests sent by the tracker actually conform to expectations, we must examine the Mountebank logs

Instead we can use a simple server which will respond correctly and write the incoming requests to a log file in a more easily parsed format.

[alexanderdean]

Sounds good Fred - please update tickets etc accordingly!