Add Travis CI & AppVeyor testing of v0.6, add test badges to README.md

[ScottPJones]

No description provided.

[coveralls]

Coverage remained the same at 100.0% when pulling 4a47c83 on ScottPJones:spj/test06 into 2220078 on JuliaDiffEq:master.

[coveralls]

Coverage remained the same at 100.0% when pulling 4a47c83 on ScottPJones:spj/test06 into 2220078 on JuliaDiffEq:master.

[codecov-io]

Codecov Report

Merging #2 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff          @@
##           master     #2   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           1      1           
  Lines          12     12           
=====================================
  Hits           12     12

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