Per #3051, update unit tests so that installed files are found relati… #4669

Job	Run time
Determine which jobs to run	8s
Compile MET	10m 5s
Update input data volumes	13s
Unit 1a (job1, ascii2nc)	8m 56s
Unit 1b (job1, ascii2nc_indy pb2nc_indy tc_dland tc_pairs tc_stat plot_tc tc_rmw rmw_analysis tc_...	15m 0s
Unit 1a (job2, pb2nc madis2nc pcp_combine gen_ens_prod)	7m 55s
Unit 1b (job2, met_test_scripts mode_multivar mode_graphics mtd regrid airnow gsi_tools netcdf mo...	17m 15s
Unit 1c (job1, ref_config_lead_00 ref_config_lead_12)	10m 31s
Unit 1c (job2, ref_config_lead_24 ref_config_lead_48)	10m 52s
Unit 1c (job3, ref_config_lead_36)	10m 14s
Unit 2a (job1, point_stat stat_analysis_ps)	14m 16s
Unit 2a (job2, grid_stat stat_analysis_gs)	9m 42s
Unit 2b (job1, climatology_1.0deg)	15m 5s
Unit 2a (job3, wavelet_stat stat_analysis_ws)	5m 48s
Unit 2b (job2, climatology_1.5deg)	12m 50s
Unit 2a (job4, ensemble_stat stat_analysis_es)	6m 10s
Unit 2b (job3, climatology_2.5deg)	12m 16s
Unit 2a (job5, ugrid)	5m 47s
Unit 2b (job4, climatology_mixed)	6m 22s
Unit 2a (job6, grid_weight point_weight)	5m 55s
Unit 2b (job5, python point2grid plot_data_plane mode mode_analysis perc_thresh hira plot_point_o...	12m 7s
Unit 2c (job1, ref_config)	3m 1s
Check for Differences	3m 29s
Update Truth Data	0s
Merge Log Artifacts	4s
	3h 24m 1s

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