* update paddle/tensor, test=develop

* update linalg,py, test=develop

* update nn/functional, test=develop

* delete paddle/tensor/*, test=develop

* merge upstream, test=develop

* update __init__, test=develop

* pass ci, test=develop

add new tensor: max,min,t,eye,log1p; test=develop

* add eye op,test=document_preview test=develop

* fix the API.spec, test=develop

* fix the document, test=document_preview test=develop

* add unitest for CI coverage, test=develop