add ucloudstack product and improve testing

[yufeiminds]

FEATURES:

• Add ucloudstack product

ENHANCEMENTS:

• Add deprecated decorator

[codecov-commenter]

Codecov Report

Merging #50 into master will increase coverage by 2.27%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #50      +/-   ##
==========================================
+ Coverage   91.60%   93.88%   +2.27%     
==========================================
  Files          19       19              
  Lines         572      572              
==========================================
+ Hits          524      537      +13     
+ Misses         48       35      -13     

Impacted Files	Coverage Δ
ucloud/core/utils/deco.py	100.00% <100.00%> (+100.00%)	⬆️

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