* chore(backend): tidy go.mod and update tools.go
* go install, instead of go get
* fix problems reported by go vet
* simplify some ide reported redundant syntax
* license is not required for generated code
* remove licenses for generated code
* cleanup
* remove license more
* rm unused BUILD.bazel files
* fixed generate_api.sh
* reimport error.proto
* include namespace in CreateVisualization
* include namespace in post body
* put namespace in the path and in front of visualization
* post /apis/v1beta1/visualizations/{namespace}
Yuan (Bob) Gong
Yang Pan
Chen Sun
jingzhang36
Kirin Patel