[R-package] Add R logo (fixes #3331, #3332)#3336

Merged

jameslamb merged 8 commits intomasterfrom feat/hex-logo

Aug 30, 2020

+85-2

Commits on Aug 28, 2020

uploaded hex logo for R-package in SVG format (#3340 )
StrikerRUS
authored

Commits on Aug 29, 2020

remove duplicate logo and fix CI
jameslamb
committed

Commits on Aug 30, 2020