update unit testing

[Paul-Carvalho]

Add test-function.R to tests/testthat folder. These test scripts should mirror the structure of files in the R folder of the FishSET package and should be designed to ensure that functions are working properly while we continue to develop and update the package.

Prioritize functions below (when complete add branch # next to items in list):

• [x] load_maindata()
• [x] load_spatial()
• [ ] load_port()
• [ ] table_view()
• [ ] plot_spat()
• [ ] fleet_table()
• [ ] fleet_assign()
• [ ] summary_stats()
• [ ] pretty_tab_sb()
• [ ] na_filter()
• [ ] nan_filter()
• [ ] unique_filter()
• [ ] empty_vars_filter()
• [ ] degree()
• [ ] spatial_qaqc()
• [ ] pretty_lab()
• [ ] pretty_tab()
• [ ] data_parser()
• [ ] cpue()
• [ ] outlier_table()
• [ ] outlier_plot()
• [ ] percent_rank()
• [ ] assignment_column()
• [ ] agg_helper()
• [ ] zone_summary()
• [ ] temp_plot()
• [ ] xy_plot()
• [ ] corr_out()
• [ ] vessel_count()
• [ ] species_catch()
• [ ] density_plot()
• [ ] sparsetable()
• [ ] sparsplot()
• [ ] create_centroid()
• [ ] create_alternative_choice()
• [ ] alt_choice_list()
• [ ] create_expectations()
• [ ] check_model_data()
• [ ] make_model_design()
• [ ] discretefish_subroutine()
• [ ] model_params()
• [ ] model_fit_summary()

[Paul-Carvalho]

Prioritize functions used in vignettes