Flaky specs with `protocol.rb:176:in 'rbuf_fill': Net::ReadTimeout (Net::ReadTimeout) error `

https://gitlab.com/gitlab-org/gitlab-ee/-/jobs/43229333

/usr/local/lib/ruby/2.3.0/net/protocol.rb:176:in `rbuf_fill': Net::ReadTimeout (Net::ReadTimeout)
    from /usr/local/lib/ruby/2.3.0/net/protocol.rb:154:in `readuntil'
    from /usr/local/lib/ruby/2.3.0/net/protocol.rb:164:in `readline'
    from /usr/local/lib/ruby/2.3.0/net/http/response.rb:40:in `read_status_line'
    from /usr/local/lib/ruby/2.3.0/net/http/response.rb:29:in `read_new'
    from /usr/local/lib/ruby/2.3.0/net/http.rb:1423:in `block in transport_request'
    from /usr/local/lib/ruby/2.3.0/net/http.rb:1420:in `catch'
    from /usr/local/lib/ruby/2.3.0/net/http.rb:1420:in `transport_request'
    from /usr/local/lib/ruby/2.3.0/net/http.rb:1393:in `request'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/webmock-2.3.2/lib/webmock/http_lib_adapters/net_http.rb:97:in `block in request'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/webmock-2.3.2/lib/webmock/http_lib_adapters/net_http.rb:105:in `block in request'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/webmock-2.3.2/lib/webmock/http_lib_adapters/net_http.rb:137:in `start_with_connect_without_finish'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/webmock-2.3.2/lib/webmock/http_lib_adapters/net_http.rb:104:in `request'
    from /usr/local/lib/ruby/2.3.0/net/http.rb:1142:in `get'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/selenium-webdriver-3.5.0/lib/selenium/webdriver/common/service.rb:124:in `block in stop_server'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/selenium-webdriver-3.5.0/lib/selenium/webdriver/common/service.rb:105:in `block in connect_to_server'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/webmock-2.3.2/lib/webmock/http_lib_adapters/net_http.rb:123:in `start_without_connect'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/webmock-2.3.2/lib/webmock/http_lib_adapters/net_http.rb:150:in `start'
    from /usr/local/lib/ruby/2.3.0/net/http.rb:584:in `start'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/selenium-webdriver-3.5.0/lib/selenium/webdriver/common/service.rb:101:in `connect_to_server'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/selenium-webdriver-3.5.0/lib/selenium/webdriver/common/service.rb:124:in `stop_server'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/selenium-webdriver-3.5.0/lib/selenium/webdriver/common/service.rb:79:in `stop'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/selenium-webdriver-3.5.0/lib/selenium/webdriver/chrome/driver.rb:68:in `quit'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/capybara-2.15.1/lib/capybara/selenium/driver.rb:276:in `quit'
    from /builds/gitlab-org/gitlab-ee/vendor/ruby/2.3.0/gems/capybara-2.15.1/lib/capybara/selenium/driver.rb:32:in `block in browser'`

Looks like something is running either as part of capybara specs or with all our specs but failing when webmock is being used together.

From that build the specs that have :js in it are (which I believe selenium is running):

• spec/features/merge_requests/conflicts_spec.rb

• spec/features/projects/commit/user_reverts_commit_spec.rb

• spec/features/projects/path_locks_spec.rb

• spec/features/issuables/markdown_references_spec.rb

• spec/features/projects/commit/cherry_pick_spec.rb

• spec/ee/spec/features/epics/epic_issues_spec.rb

• spec/features/projects/mirror_spec.rb

• spec/features/projects/branches_spec.rb

• spec/features/snippets/show_spec.rb

• spec/features/merge_requests/closes_issues_spec.rb