Remove jasmine-fixture, use teaspoon fixtures

spec/javascripts/fixtures/issuable.html.haml

spec/javascripts/fixtures/issue_note.html.haml

spec/javascripts/fixtures/issues_show.html.haml

spec/javascripts/fixtures/merge_requests_show.html.haml

spec/javascripts/issue_spec.js.coffee

spec/javascripts/merge_request_spec.js.coffee

spec/javascripts/notes_spec.js.coffee

spec/javascripts/shortcuts_issuable_spec.js.coffee

vendor/assets/javascripts/jasmine-fixture.js