add codecov component #992

[lovepoem]

What is the purpose of the change

#992

Brief changelog

update pom.xml
.travis.yml

we can get:
the test coverage rate of the entire project
coverage rate change of every PR

[chickenlj]

Hello, lovepoem. Have u test this in your own repository?

[lovepoem]

Yes. https://github.com/lovepoem/codecov-travis-maven-test is a new repository I created for this issue three days ago .

Please see the examples:
https://github.com/lovepoem/codecov-travis-maven-test
lovepoem/codecov-travis-maven-junit4-example#3

dubbo code master should do with github account：
login https://travis-ci.org/ and add dubbo repository to https://travis-ci.org/ (it seems done)
login https://codecov.io/ and add dubbo repository to https://codecov.io/

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@da0f63e). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #993   +/-   ##
=========================================
  Coverage          ?   27.53%           
=========================================
  Files             ?      789           
  Lines             ?    41577           
  Branches          ?     8476           
=========================================
  Hits              ?    11449           
  Misses            ?    28079           
  Partials          ?     2049

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[chickenlj]

Is CodeCov necessary? I find many other github projects haven't integrate with CodeCov.
Will it help us to figure out whether a PR has enough UT?

[lovepoem]

I think a rich test case is necessary for the quality of the code. Travis Ci and codecov were only popular in the last two years. Codecov does help us check every PR test code and improve the test code coverage.