Allow user to disable beta, canary when using versionCompatability

[ghost]

My test suite on beta/canary right now is running into an infinite loop (due to an Ember.js bug), causing it to run for 59 minutes until Travis CI kills it.

[kategengler]

Would love a PR to handle an enabled option on each scenario, for now, as a hack, you could use something like this config:

/*jshint node:true*/

module.exports = function() {
  return {
    useVersionCompatibility: true,
    scenarios: [
      {
        name: 'ember-beta',
        command: './fail.sh'
      },
      {
        name: 'ember-canary',
        command: 'echo DISABLED'
      }
    ]};
};

When the config has useVersionCompatibility: true the scenarios will merge with the auto-generated ones. Run ember try:config to see what config it will run with.

You can override the command to something harmless like echo or make a script that exits non-zero to fail the scenario.

[ghost]

Hey thanks! That worked and is a totally fine for a temp fix! :)

[kategengler]

Closing as it should be covered by the solution to #155