message: test(docs-infra): prevent warning due to missing expectation
  Fix a unit test warning due to Jasmine not realizing that
  `httpMock.expectOne()` is an expectation.
  [Example][1]:
  > WARN: 'Spec 'DocumentService currentDocument should encode the request
  > path to be case-insensitive' has no expectations.'
  [1]:
  PR Close
diff: @@ -70,6 +70,8 @@ describe('DocumentService', () => {
  it('should encode the request path to be case-insensitive', () => {
  const { docService, locationService } = getServices('initial/Doc');
  docService.currentDocument.subscribe();
  +
  + expect(() => {
  httpMock.expectOne(CONTENT_URL_PREFIX + 'initial/d_oc.json').flush({});
  locationService.go('NEW/Doc');
  httpMock.expectOne(CONTENT_URL_PREFIX + 'n_e_w_/d_oc.json').flush({});
  @@ -77,6 +79,7 @@ describe('DocumentService', () => {
  httpMock.expectOne(CONTENT_URL_PREFIX + 'doc__with__underscores.json').flush({});
  locationService.go('DOC_WITH_UNDERSCORES');
  httpMock.expectOne(CONTENT_URL_PREFIX + 'd_o_c___w_i_t_h___u_n_d_e_r_s_c_o_r_e_s_.json').flush({});
  + }).not.toThrow();
  });
  it('should emit the not-found document if the document is not found on the server', () => {
  