hx-boost attribute

• handles basic anchor properly10ms ‣

  this.server.respondWith('GET', '/test', 'Boosted')
  var div = make('<div hx-target="this" hx-boost="true"><a id="a1" href="/test">Foo</a></div>')
  var a = byId('a1')
  a.click()
  this.server.respond()
  div.innerHTML.should.equal('Boosted')