Remove all references to jsoncpp (build scripts, DEPS, etc)

Bug: skia:
Change-Id: I3cec245e537eee3e6ceb0a4a52bad733c2c8746e
Reviewed-on: https://skia-review.googlesource.com/c/189842
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
5 files changed