#65 implemented GET /technologies.

Implemented Issue #65 GET /technologies following the implementation of GET /categories. Thanks @tgkokk

I have some questions about mocha test.
- It takes too long to complete one test. This is because it runs an actual server and sends actual requests. It's working but does not seem to be the best practice. We need to find a way to use mock system.
- Is it decided to use 'asset' style? Not important, but I personally prefer 'should' style.