Remove Travis and correct README badges

[codecov-commenter]

Codecov Report

Patch and project coverage have no change.

Comparison is base (b4652c7) 91.82% compared to head (7bd002f) 91.82%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## trunk #152 +/- ## ======================================= Coverage 91.82% 91.82% ======================================= Files 11 11 Lines 1260 1260 ======================================= Hits 1157 1157 Misses 103 103 ```

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[gliptak]

@glyph please review