#56 add lightweight C/C++ unit testing framework ciut

Suggest this C/C++ unit test framework for it supports auto register functions, less user interruption compared to other libraries, single header file and no other extra library files; the test cases can be as simple as "TEST_CASE() { REQUIRE(0 == 1); }", or customized with arguments such as "TEST_CASE( .skip=1 ){}" using the same interface.

Thank you for your contribution! I think this is indeed a good library, and I'd like to add it. However, there's just two small changes I'd like:

• Add some documentation about the assertions the unit test library supports (currently, there's only a very basic example)
• Remove the mention in this list that this is a C/C++ library, as this is not relevant in this case (as per the heading of this project)

Once these changes are made, I would be happy to merge.

Any progress on this @yhfudev?

@koz.ross,

I updated the patches according to your comments, thanks!

@yhfudev I apologise that this took so long - life caught up with me badly. It's merged now - thank you so much for your contribution!