Add experimental React+Redux Jest test

frontend/src/metabase/components/EmptyState.jsx

...tend/src/metabase/dashboards/components/DashboardList.jsx

...rc/metabase/dashboards/containers/Dashboards.spec.data.js

...end/src/metabase/dashboards/containers/Dashboards.spec.js

...shboards/containers/__snapshots__/Dashboards.spec.js.snap

frontend/src/metabase/lib/formatting.js

frontend/test/__mocks__/fileMock.js

frontend/test/__mocks__/styleMock.js

package.json

yarn.lock