[vuln_commands,test_commands] legends options changed to titles option

for histograms.

bob/pad/base/script/vuln_commands.py

@@ -324,7 +324,7 @@ def epsc(ctx, scores, criteria, var_param, fixed_param, three_d, sampling,
     'If False, will annotate the plots hypothetically, instead '
     'of with real data values of the calculated error rates.', True
 )
-@common_options.legends_option()
+@common_options.titles_option()
 @common_options.const_layout_option()
 @common_options.figsize_option(dflt=None)
 @common_options.subplot_option()

bob/pad/base/test/test_commands.py

@@ -110,7 +110,7 @@ def test_hist_vuln():
     with runner.isolated_filesystem():
         result = runner.invoke(vuln_commands.hist,
                                ['--criterion', 'eer', '--output',
-                                'HISTO.pdf', '-b', '30',
+                                'HISTO.pdf', '-b', '30', '-ts', 'A,B',
                                 licit_dev, licit_test])
         assert result.exit_code == 0, (result.exit_code, result.output)