[GRASS-git] [OSGeo/grass] 52b3cc: readme: Convert to markdown and add travis badge

[pmav99]

  Branch: refs/heads/releasebranch_7_4
  Home:   https://github.com/OSGeo/grass
  Commit: 52b3cce5b548df9b975f80ebf9799176ba6cb04d
      https://github.com/OSGeo/grass/commit/52b3cce5b548df9b975f80ebf9799176ba6cb04d
  Author: Panos Mavrogiorgos <pmav99 at gmail.com>
  Date:   2019-05-26 (Sun, 26 May 2019)

  Changed paths:
    R README
    A README.md

  Log Message:
  -----------
  readme: Convert to markdown and add travis badge

Updated to GRAS GIS 7.4