Changed wording for clarity in README.md

[BradyBromley]

• With pull requests:
  • Open your pull request against master
  • Your pull request should have no more than two commits, if not you should squash them.
  • It should pass all tests in the available continuous integrations systems such as TravisCI.
  • You should add/modify tests to cover your proposed code changes.
  • If your pull request contains a new feature, please document it on the README.

[codecov]

Codecov Report

Merging #2122 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2122   +/-   ##
=======================================
  Coverage   98.61%   98.61%           
=======================================
  Files          40       40           
  Lines        2238     2238           
=======================================
  Hits         2207     2207           
  Misses         16       16           
  Partials       15       15

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b52a1a1...d60d9a9. Read the comment docs.