Not very surprising, the makefile diddn't work for multiple .cpp files in unit_test (it just ignored them).

This should fix it so that it produces objects from all .cpp files and adds them into the executable.
(cherry picked from commit 7c198667b022a995a4accac0f04339affa3c09e7)
Merge branch 'develop' of github.com:alcap-org/AlcapDAQ into develop
Tidy up.