Making use of constant

Upgrade bor dependencies

use go-ethereum for better forked-bor release  and geth v1.9.24 upgrade

new: add bor apis

Test changes

Bor related changes on updated geth

fix: changed geth to bor for docker

Update master

This fixes cross-build and mobile framework failures.
It also disables the mac test builder because it was failing
all the time in hard to understand ways and we can't afford
it anymore under Travis CI's new pricing.

* Bit boundary fix for the DAG generation routine

* Fix unnecessary conversion warnings

Co-authored-by: Sergey Pavlov <spavlov@gmail.com>

This new flag downloads a known version of Go and builds with it. This
is meant for environments where we can't easily upgrade the installed Go
version.

* .travis.yml: remove install step for PR test builders

We added this step originally to avoid re-building everything
for every test. go test has become much smarter in recent go
releases, so we no longer need to install anything here.