Update .travis.yml and appveyor.yml and update links in README.md

[andreasnoack]

Hopefully, this should get coverage running again.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@efb06cd). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master      #51   +/-   ##
=========================================
  Coverage          ?   58.47%           
=========================================
  Files             ?        6           
  Lines             ?      301           
  Branches          ?        0           
=========================================
  Hits              ?      176           
  Misses            ?      125           
  Partials          ?        0

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