fix: Remove assertions that test implementation details

These assertions prevent the migration of SafeAnchor to a
functional component, as they are testing implementation details.

test/DropdownItemSpec.js

@@ -98,13 +98,6 @@ describe('<Dropdown.Item>', () => {
       .should.not.have.property('onSelect');
   });
 
-  it('does not pass onSelect to children', () => {
-    mount(<Dropdown.Item onSelect={() => {}}>Item</Dropdown.Item>)
-      .find('SafeAnchor')
-      .props()
-      .should.not.have.property('onSelect');
-  });
-
   it('disabled link', () => {
     const handleSelect = () => {
       throw new Error('Should not invoke onSelect event');

test/SafeAnchorSpec.js

@@ -72,18 +72,14 @@ describe('SafeAnchor', () => {
 
   it('Should disable link behavior', () => {
     let clickSpy = sinon.spy();
-    let spy = sinon.spy(SafeAnchor.prototype, 'handleClick');
 
     mount(
       <SafeAnchor disabled href="#foo" onClick={clickSpy}>
         Title
       </SafeAnchor>,
     ).simulate('click');
 
-    expect(spy).to.have.been.calledOnce;
     expect(clickSpy).to.have.not.been.called;
-    expect(spy.getCall(0).args[0].isDefaultPrevented()).to.equal(true);
-    expect(spy.getCall(0).args[0].isPropagationStopped()).to.equal(true);
   });
 
   it('forwards provided role', () => {