Generate events and checks client

[indigok]

Part of #1157. Generalizes the openapi_generator to work with the events and checks clients and removes hard coded values from the tests. The major changes are replacing check_run in method names to just check:

events.rb

repository_events => repo_events
organization_events => org_events, also adds user param
organization_public_events => org_public_events

the same:
public_events, user_events, user_public_events,

checks.rb

create_check_run => create_check
update_check_run => update_check
check_runs_for_check_suite => check_suites
check_run => check
check_run_annotations => check_annotations
set_check_suite_preferences => set_suite_preferences

the same:
check_suite, create_check_suite, rerequest_check_suite

Methods removed for now as they'll be generated in other files,
received_events, received_public_events(user.rb),
repository_network_events (networks.rb)
repository_issue_events => repository_events (issues.rb)
issue_events, issue_event (issues.rb)
check_runs_for_ref, check_suites_for_ref (commits.rb)

Retroactively:

move_project_column and move_project_card now return a boolean response

[tarebyte]

Looking good!