[Test Do Not Merge]Update .travis.yml

[yufangong]

Problem

Explain the context and why you're making that change. What is the problem you're trying to solve? In some cases there is not a problem and this can be thought of being the motivation for your change.

Solution

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Result

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[CLAassistant]

All committers have signed the CLA.

[cacoco]

@yufangong we're likely going to need to put 2.13 into a matrix that doesn't fail the build, akin to the netty snapshot stuff. We may actually still have Scrooge or TwitterServer set up this way as well.

See: https://github.com/twitter/twitter-server/blob/develop/.travis.yml#L39

[codecov[bot]]

Codecov Report

Merging #549 into develop will not change coverage. The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #549   +/-   ##
========================================
  Coverage    90.75%   90.75%           
========================================
  Files          267      267           
  Lines         4779     4779           
  Branches       301      301           
========================================
  Hits          4337     4337           
  Misses         442      442           

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