Fix plot logo and tight layout bug (#213)

Fix the fatal error that results from a batch plot input yaml file
containing `plot logo` and/or `tight layout` figure settings.

As described in #212 the problem is that in
`src/eva/plotting/batch/base/plot_tools/figure_driver.py` both `plot
logo` and `tight layout` are left in the `figure_conf` dictionary after
the corresponding figure method is correctly applied. The `figure_conf`
dictionary is eventually fed to `emcpy` and then `matplotlib` which is
unable to parse these entries. The fix is to simply remove the entries
from `figure_conf` once the requested method has been called.

Testing has been done on hera using
`src/eva/tests/config/testMonDataSpaceHirs4Metop-A.yaml`, which now can
plot logos and use tight layout.

Closes #212

src/eva/plotting/batch/base/plot_tools/figure_driver.py

@@ -241,8 +241,11 @@ def make_figure(handler, figure_conf, plots, dynamic_options, data_collections,
             fig.tight_layout(**figure_conf['tight layout'])
         else:
             fig.tight_layout()
+        figure_conf.pop('tight layout')
+
     if 'plot logo' in figure_conf:
         fig.plot_logo(**figure_conf['plot logo'])
+        figure_conf.pop('plot logo')
 
     saveargs = get_saveargs(figure_conf)
     fig.save_figure(output_file, **saveargs)

src/eva/tests/config/testMonDataSpaceHirs4Metop-A.yaml

@@ -30,9 +30,10 @@ graphics:
         figure size: [12,10]
         title: 'hirs4_metop-a | Channel 1 | Obs Count'
         output name: lineplots/hirs4_metop-a/hirs4_metop-a.0.count.png
-        #plot logo:
-        #  which: 'noaa/nws'
-        #  loc: 'upper right'
+        plot logo:
+          which: 'noaa/nws'
+          loc: 'upper right'
+        tight layout:
       plots:
         - add_xlabel: 'Cycle Time'
           add_ylabel: 'Observation Count'