Updated README.md
HostIlE - IE11 connects to a wrong host in cross domain scenarios when a relative connection url is used (fixes #2959)

When parsing a relatinve uri with <a /> (anchor) IE11 does not provide the protocol so we fall back to using `window.document.location` to resolve connection details. However if the host could be read from the url provided by the user we should use it instead of the one from the `window.document.location`. The fix is to use the host from the url provided by the user if possible and fall back to using the host from the `window.document.location` if the host could not be read from the user's url.
Silence!

Baselining Chutzpah coverage report to prevent from showing the file as modified each time build.cmd is run.
Made HubCallerContext easier for mock unit testing

#3012
Made changes as per code review feedback

#3105