Fixes for capybara poltergeist tests on Scott's machine

The poltergeist tests were timing out on my machine unless I
did 2 things: 1. skipped rendering of social sharing widgets
2. loaded a simple page before loading the real page
This commit applies both of these changes to all js tests.
Lightweight_activity.rb : Add run collection to activity model.
Unit test for SequenceRun
Add Travis CI configuration

as per http://about.travis-ci.org/docs/user/getting-started/
Tweaking travis configuration (have to push to trigger a build sorry… )
Change 'See This Page' to 'Preview'.  [#55994072]

https://www.pivotaltracker.com/story/show/55994072
Fix spelling problem: [#56010414]

When image question not answered, activity page summary shows "Not Ansered" instead of "Not Answered"
This was interacting badly with changes to spec_helper (visit ! defined)

Capybara adds DSL to support things like "visit" but not to spec/views

This before filter ran even though this was a pending test:
https://github.com/concord-consortium/lara/blame/master/spec/spec_helper.rb#L74-L77

In the context of this test in spec/views 'visit' is not defined.
Tavis CI isn't calling rake db:migrate like I would hope it would...
Add Travis and Code-Climate badges to the README.
Gemfile: Add time cop for time-sensitive testing.  (bundle install req)
All activities/sequences indexes should sort by last modified date.

https://www.pivotaltracker.com/story/show/55992946
Home page listing of activities/sequences should be sorted by modtime.

[#55992946]  https://www.pivotaltracker.com/story/show/55992946
Merge branch 'master' into staging

* master:
  Home page listing of activities/sequences should be sorted by modtime.
  All activities/sequences indexes should sort by last modified date.
  Gemfile: Add time cop for time-sensitive testing.  (bundle install req)
  Add Travis and Code-Climate badges to the README.
  Tavis CI isn't calling rake db:migrate like I would hope it would...
  This was interacting badly with changes to spec_helper (visit ! defined)
  Fix spelling problem: [#56010414]
  Change 'See This Page' to 'Preview'.  [#55994072]
  Tweaking travis configuration (have to push to trigger a build sorry… )
  Add Travis CI configuration
  Unit test for SequenceRun
  Lightweight_activity.rb : Add run collection to activity model.
  Fixes for capybara poltergeist tests on Scott's machine