[capnproto] Add Capnproto package#5617

Merged

Rastaban merged 3 commits intomicrosoft:masterfrom

Mar 26, 2019

Commits on Mar 10, 2019

Add Capnproto package
tarcila
committed

Commits on Mar 11, 2019

Fix tools/ and add support vcpkg_test_cmake()
tarcila
committed

Commits on Mar 22, 2019

Disable cmake integration test for now
tarcila
committed