improve test cases & upgrade dependencies

[JacksonTian]

No description provided.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@3956f0a). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master      #21   +/-   ##
=========================================
  Coverage          ?   82.80%           
=========================================
  Files             ?        1           
  Lines             ?      157           
  Branches          ?       40           
=========================================
  Hits              ?      130           
  Misses            ?       27           
  Partials          ?        0           

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[coveralls]

Coverage increased (+2.7%) to 81.633% when pulling 671728f on improve_test into 3956f0a on master.