First pass of exposing an endpoint to publish a Lara sequence.
Ignore new-style ruby version and gem set files
WIP: specs for the new sequence-aware publish API
WIP on publishing sequences (mostly tests)
Functioning spec for activity_runtime_api
activity_runtime_api factors out activity creation

This pulls out the actual creation of activities and child components from the hash into its own method, so it can be used both by publish_activity and publish_sequence.
API passes unit testing for publishing sequences
WIP on publishing sequences: glitches testing updates

[#53637857]

https://www.pivotaltracker.com/story/show/53637857
Fixes test setup for sequence updating via API.

This should finish support for publishing and updating sequences using the same endpoint as the existing activity-publishing API, once it's checked against the client (LARA). [#53637857]

https://www.pivotaltracker.com/story/show/53637857
Fixing scope of @existing_sequence creation

[#53637857] Getting the tests right.

https://www.pivotaltracker.com/story/show/53637857
All publishing API features pass (except magic)
Tweak cucumber tests for sequence publishing API
Add Image_question to the activty_runtime_api

Conflicts:
	lib/activity_runtime_api.rb
ProcessExternalActivityDataJob -- adding image question answers.

proceess_external_activity_data_job.rb: support  image_question
&update spec / features
activity_runtime_api_spec.rb :  Fix broken test, external_id is a string
Fix typo in spec.
Merge branch 'master' into publish_sequence

Conflicts:
	lib/activity_runtime_api.rb
external activity api: cache activities by name

When updating, activities were using 'url' as a hash key, but they don't have that attribute.
Fix failing specs re: anonymous_can_browse_materials

Mock Project's received unknown message :anonymous_can_browse_materials

Removed comment from one test
(cherry picked from commit d2b57b601eb963fcde175c2b133937776780d349)
manualy merge pulish feature