Test for Essential functions TODO list.

[hzhangxyz]

• arithmetic (Test/add test for arithmetic #41) (Add mismatch case in test of arithmetic operators. #55)
• masking (Add tests for masking. #40)
• permute (Add test for permute. #45) (Add one high order permute test case. #47) (Add corner case for test of permute and reverse. #57)
• reverse (Add tests for reverse. #46) (Add corner case for test of permute and reverse. #57)
• split edge (Add tests for reshape function. #48) (reshape need more tests. #58) (Add support for trivial edges in reshape function #64) (Fix issue when reshape with none edge. #67) (Fix corner cases in reshape and improve its robustness #72)
• merge edge (Add tests for reshape function. #48) (reshape need more tests. #58) (Add support for trivial edges in reshape function #64) (Fix issue when reshape with none edge. #67) (Fix corner cases in reshape and improve its robustness #72)
• contract (Add support for matmul. #59) (matmul need more tests. #60) (Add more tests for matmul. #61) (Add assertion tests for matmul of impure tensors #69)
• trace (dev/add support for trace #68)
• conjugate
• svd (Add support for svd #70)
• qr
• identity (Add support for identity #77)
• exponential (Add support for exponential #75) (Add support for identity #77)

Some functions are not implemented yet, details in (#15).