Fixes errors when logging from std::cout and std::cerr.

Fixes errors when logging from std::cout and std::cerr calls (e.g., notarius::cout and notarius::cerr).
Adds test suite: 'notarius_std_cout_cerr_test'

Fixes gcc warnings

Fixes gcc warnings

v0.1.8

Minor performance improvement using std::string_view sv literal which is more efficient than constructing a std::string.

notarius_t - A C++ Header Only Logging Library

Goals:

• It should remain as a single header only (other than STL headers). The only file needed for projects is notarius.hppand a modern C++ library. Although additional files are contained in the ./include/notarius path, these files are not required and are only provided for test project support.
• Note that performance is variable across compilers and machines. On Windows it will generally be 2x faster than spdlog and near equal to spdlog on Linux and Apple.
• Easy to use (e.g., easy configurability of logging instances, and, the implementation of the source code should be easy to read and understand).
• Thread safety that can be turned off when not required.
• Notarius is easy to modify and may be used as a starting point for your own custom logger.