Running tests without previously running make install fails.

Running tests without having previously run make install fails. The reason is that both libnorns.so and libnornsctl.so try to initialize themselves when the test program starts, and fail to do so since they can't find the default configuration file (which has not been installed yet).

The exact error message can be seen by setting the NORNS_DEBUG_OUTPUT_TO_STDERR environment variable prior to running the test:

<libnornsctl>: [libnornsctl.c:61 load_config_file()] DEBUG: Loading configuration file "/usr/local/etc/norns.conf"
<libnornsctl>: [libnornsctl.c:64 load_config_file()] FATAL: Failed to access norns configuration file: No such file or directory