Optimised random port generation.
Splitting main.c into app.h app.c and main.c, so that main function is the only one in main.c and we can write tests for the other functions. Also created test folder for tests.
Test infrastructure in makefile and run_tests.sh, as well as test for optimised implementation of random_in_range.
Renaming test directory to tests and changing Makefile target to test. I was getting a clash if both were the same.
Ignoring tags file.
Merge pull request #1 from draganglumac/testable

Testable - making the test infrastructure and the first test for changed implementation of random_in_range