Format using blackdoc and fix flake8 error

Author: weiji14

pygmt/helpers/utils.py

@@ -164,7 +164,8 @@ def build_arg_string(kwargs):
     ...         dict(
     ...             B=["af", "WSne+tBlank Space"],
     ...             F='+t"Empty  Spaces"',
-    ...             l="'Void Space'"),
+    ...             l="'Void Space'",
+    ...         ),
     ...     )
     ... )
     -BWSne+tBlank\040Space -Baf -F+t"Empty\040\040Spaces" -l'Void\040Space'

pygmt/tests/test_figure.py

@@ -116,7 +116,7 @@ def test_figure_savefig_filename_with_spaces():
     fig.basemap(region=[0, 1, 0, 1], projection="X1c/1c", frame=True)
     with GMTTempFile(prefix="pygmt-filename with spaces", suffix=".png") as imgfile:
         fig.savefig(imgfile.name)
-        assert not r"\040" in os.path.abspath(imgfile.name)
+        assert r"\040" not in os.path.abspath(imgfile.name)
         assert os.path.exists(imgfile.name)