Introduce build minutes (again)

Closes #1405

See merge request !1078

Introduce build minutes

Closes #1405

See merge request !965

Revert "Merge branch 'introduce-build-minutes' into 'master'"

See merge request !1077

This reverts merge request !965

Introduce build minutes

Closes #1405

See merge request !965

Port of simple-eslint-fixes to EE

See merge request !1049

Time tracking api EE

See merge request !1073

New endpoints are:

POST :project_id/(issues|merge_requests)/(:issue_id|:merge_request_id)/time_estimate"

POST :project_id/(issues|merge_requests)/(:issue_id|:merge_request_id)/reset_time_estimate"

POST :project_id/(issues|merge_requests)/(:issue_id|:merge_request_id)/add_spent_time"

POST :project_id/(issues|merge_requests)/(:issue_id|:merge_request_id)/reset_spent_time"

GET  :project_id/(issues|merge_requests)/(:issue_id|:merge_request_id)/time_stats"

Small formatting/syntax fixes

See merge request !1070

MR Approvals Frontend-Backend Integration

Closes #1262, #894, and #1287

See merge request !954

Refactored 1st iteration of cycle analytics and stages in general (EE version)

See merge request !1064

[EE] Add a `:repository` trait to the `:empty_project` factory

See merge request !1068

Fix double spacing for code blocks
Format exception

CE upstream

See merge request !1065

Copy commit SHA to clipboard

See merge request !1066

Right now this is a no-op. We're going to add it as a trait argument to
all existing usages of the `:project` factory, so that later we can flip
`:empty_project` to just be `:project`, forcing developers to opt-in to
the slower option when their tests truly require it.