unittest_nntrainer_layers is disabled

[lhs8928]

• This unittest have been disabled from commit f519056 in #1281. (Last commit that this unittest works is fe87882c)
• Now we have done refactoring the layers, it needs to be enabled but it is using outdated interfaces and we develop new unittest for layers.

Following unit test is considerable.

• negative setProperty unittest
• with activation
• with optimizer
• with loss

[taos-ci]

:octocat: cibot: Thank you for posting issue #2002. The person in charge will reply soon.