fix docs, fix license, fix lint, fix test，enhance install

[sjmshsh]

What is the purpose of the change

XXXXX

Brief changelog

XX

Verifying this change

XXXX

Follow this checklist to help us incorporate your contribution quickly and easily:

• Make sure there is a Github issue filed for the change (usually before you start working on it). Trivial changes like typos do not require a Github issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
• Format the pull request title like [ISSUE #123] Fix UnknownException when host config not exist. Each commit in the pull request should have a meaningful subject line and body.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist.
• Run `mvn clean compile --batch-mode -DskipTests=false -Dcheckstyle.skip=false -Drat.skip=false -Dmaven.javadoc.skip=true to make sure basic checks pass.

[chickenlj]

LGTM.

[codecov-commenter]

Codecov Report

Merging #25 (b966cad) into master (6d0d795) will increase coverage by 0.19%.
Report is 14 commits behind head on master.
The diff coverage is 45.83%.

@@            Coverage Diff             @@
##           master      #25      +/-   ##
==========================================
+ Coverage   47.25%   47.45%   +0.19%     
==========================================
  Files         117      150      +33     
  Lines        6675     9768    +3093     
  Branches       41       41              
==========================================
+ Hits         3154     4635    +1481     
- Misses       3211     4603    +1392     
- Partials      310      530     +220     

Files Changed	Coverage Δ
app/dubboctl/cmd/completion_util.go	0.00% <0.00%> (ø)
app/dubboctl/cmd/manifest_diff.go	59.80% <ø> (ø)
app/dubboctl/cmd/profile_diff.go	79.59% <ø> (ø)
app/dubboctl/cmd/profile_list.go	91.83% <ø> (ø)
app/dubboctl/internal/dubbo/deployer.go	0.00% <0.00%> (ø)
app/dubboctl/internal/dubbo/errors.go	0.00% <0.00%> (ø)
app/dubboctl/internal/kube/component.go	49.56% <ø> (ø)
app/dubboctl/internal/kube/object.go	84.03% <ø> (ø)
app/dubboctl/internal/kube/operator.go	0.00% <0.00%> (ø)
app/dubboctl/internal/kube/port_foward.go	0.00% <ø> (ø)
... and 61 more

... and 3 files with indirect coverage changes

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