Co-Authored-By: gballet <gballet@gmail.com>

Co-Authored-By: gballet <gballet@gmail.com>

This is a temporary fix, better checks need to
be performed once the whole process has been
validated.

Instead, use a go library that communicates with pcscd over a socket.

Also update the changes introduced by @gravityblast since this PR's
inception

consensus,core: shortcut uncle validation

params: set Rinkeby Petersburg fork block (4th May, 2019)

appveyor: Upgrade to go1.12.2