Bump edx-enterprise to 0.55.1.

[mtyaka]

This updates edx-enterprise to 0.55.1 to include changes related to enteprise tracking events.

JIRA Ticket: ENT-744

Testing Instructions: See openedx/edx-enterprise#246.

[openedx-webhooks]

Thanks for the pull request, @mtyaka! It looks like you're a member of a company that does contract work for edX. If you're doing this work as part of a paid contract with edX, you should talk to edX about who will review this pull request. If this work is not part of a paid contract with edX, then you should ensure that there is an OSPR issue to track this work in JIRA, so that we don't lose track of your pull request.

Create an OSPR issue for this pull request.

[mtyaka]

Quality build is failing but expected to be fixed by https://github.com/edx/edx-platform/pull/16709.

[UmanShahzad]

Yep sorry about that. I'm thinking of just merging that as it'll fix the build on master but will like to wait for confirmation.

[UmanShahzad]

👍 reviewed this on the edx-enterprise PR.

[douglashall]

jenkins run quality

[UmanShahzad]

@mtyaka One more rebase and this should be good! Sorry about that.

[mtyaka]

jenkins run lettuce

[mtyaka]

Thanks @UmanShahzad!

[edx-pipeline-bot]

EdX Release Notice: This PR has been deployed to the staging environment in preparation for a release to production on Monday, December 04, 2017.

[edx-pipeline-bot]

EdX Release Notice: This PR has been deployed to the production environment.