Resolve "Emails forwarded to Service Desk email don't come"

Closes #2247

See merge request !1810

Added find for collapsed sidebar before asserting

See merge request !1787

Remove explicit requires from lib/elasticsearch

See merge request !1807

Fix missing project attributes used by the Import/Export feature

See merge request !1727

Uses new Polling technique on the Frontend - etag

Closes #2222

See merge request !1713

Try waiting for previous dropdown to definitly close before going to click

See merge request !1806

These set the 'actual' destination email in one of the Delivered-To lines, so
check those too.

If an email doesn't match our incoming email patterns on the To header, we fall
back to the References header. If there was no References header, we'd raise an
exception, when we'd be better off acting as if it was empty.

Import the gitlab-elasticsearch-git gem

Closes gitlab-elasticsearch-git#6

See merge request !1794

Document pipeline grouping

See merge request !1757

How to Configure LDAP with GitLab EE

Closes #2101

See merge request !1784

find and match first dropdown before clicking

See merge request !1795

Support more elasticsearch versions

Closes #2253

See merge request !1716

Support advanced search queries using elasticsearch

Closes #2037

See merge request !1770

Re-enable ref operations with gitaly after not-found fix

See merge request !1758

[EE] Enable `RSpec/DescribedClass` cop and correct violations

See merge request !1721

Port of "Reject more reserved paths" to EE

See merge request !1778

Fix Geo geo:set_primary_node task not working with HTTPS

See merge request !1774

implements new logic for push mirrors to update on push

See merge request !1616

And validate if new paths need to be added.

This is a port to EE of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10413 to EE

Add a note about pipeline quota reset on the first of each month

See merge request !1772