The `clamscan_test.py` file is getting way too long.
Created a new `unit_tests/clamscan` directory and separated all tests
into separate test files.
I also fixed an issue with the clamscan `ign2` test:
The `ign2` test wasn't written correctly and was actually testing
detection despite using the `-d` parameter to try to ignore a signature.
There is a minor bug where `ign2` files may be loaded after other files
when using the `-d` option. It is only guaranteed to be loaded first if
you load all the sigs from the same directory. I fixed the test.
In the future, we should make it so all database files are sorted in a
list before load time regardless of where they're sourced from.