* upload code for tensor.rand

* fix import

* update example, change paddle.tensor.rand to paddle.rand

* change 'variable' to 'Variable',  test=develop

change 'variable' to 'Variable' in description,  test=develop

* add pre-commit check

* add pre-commit check

* pre-commit check, test=develop

* add more unittest code

* trigger ci, test=develop

* pre-commit check, test=develop

* update api and test comment, test=develop

* update api and test comment, test=develop

* add more type check, test=develop

* add detail error info for device, test=develop

* add unnittest, test=develop

* resolve conflict and pre-commit check, test=develop

Fix the dygraph mode in matmul, add the support in Linear Op

* add clamp api, test=develop

* test=develop, add seed arguemnt of randint API

* add gradient check to reduce ops

* add skip gradient check to reduce ops test=develop

* modify stack api test=develop

* add bmm op and move serval ops from fluid.layers to tensor test=develop

* add paddle.tensor
test=develop

* polish gpu where codes
test=develop

* polish test code
test=develop

change the  exponet_tensor  to  exponent_tensor  in the pow api 

* improve efficiency of dot op in dygraph mode

* add comments for dot op for dygraph behavior

* add addcmul, test=develop

test=develop

* add paddle.std api test=develop

* update  test=develop

* fix example code format test=develop

* test=develop fix api doc error

* Add variance computing layer for tensor

* Format input data types

* Remove unnecessary expand operation

* Some fixes in doc

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

* Add new API : randn

test=develop

* Add new API : randn

test=develop

* Add new API : randn

test=develop

* Add new API : randn

test=develop

* aAdd new API : randn

test=develop

* Add new API : randn

test=develop

* Add new API : randn

test=develop

* Add new API : randn

test=develop

* Add new API : randn

test=develop

* Add new API : randn

test=develop

* Add new API : randn

test=develop

* Add new API : randn

test=develop

In those ops, some api has execute run error, fix those op, and format some sample code.

* Add new norm api, support frobenius norm and p-order vector norm. test==develop
* combine test files, add more attr checks. test=develop

Those ops include，scale， sum， sums，unique_with_counts，unique，
wherre， add error message and test case

* add dist op

add addmm op

* add full_like op. test=develop

* add dygraph support. test=develop

* increase coverage. test=develop

* add randint op

* rename op paddle.fluid.matmul to paddle.matmul
* modify original API fluid.layers.matmul,and add new API paddle.matmul

* add index_sample op

* Add the matmul, elementwise_euqal, elementwise_sum ops to API2.0
* Fix the import meesage in common_ops_import
* Update the test cast for mm

* Add the sum op to API 2.0, test=develop
* Fix the import meesage in common_ops_import

*  add new op paddle.tensor.mul(x, y, x_num_col_dims=1, y_num_col_dims=1, out=None, name=None)
* add new op paddle.tensor.pow(input, exponent, out=None, name=None)
* add the aboved two new ops unittest (test api param out and name)

add tril op and  triu op

* add new op paddle.tensor.div(x, y, out=None, name=None) 
* add gpu and dygraph unittests.
* Performance optimization: scale op is not called when alpha=1. 
* op error message optimization.