Remove HTML Output File from example12_DH.txt to avoid annoying litte…

…ring of generated files; test HTML output in separate test that outputs to a temp directory instead

tests/examples/example12_DH.txt

@@ -60,4 +60,3 @@ Fracture Height, 300
 Fracture Width, 200
 Fracture Shape, 4
 Well Drilling and Completion Capital Cost, 12
-HTML Output File, example12_DH.html

tests/geophires_x_tests/test_outputs.py

@@ -1,14 +1,30 @@
 import os
 import sys
+import tempfile
 from pathlib import Path
 
 from geophires_x.Model import Model
 from geophires_x_client import GeophiresInputParameters
+from geophires_x_client import GeophiresXClient
 from tests.base_test_case import BaseTestCase
 
 
 class OutputsTestCase(BaseTestCase):
 
+    def test_html_output_file(self):
+        html_path = Path(tempfile.gettempdir(), 'example12_DH.html').absolute()
+        GeophiresXClient().get_geophires_result(
+            GeophiresInputParameters(
+                from_file_path=self._get_test_file_path('../examples/example12_DH.txt'),
+                params={'HTML Output File': str(html_path)},
+            )
+        )
+        self.assertTrue(html_path.exists())
+        with html_path.open() as f:
+            html_content = f.read()
+            self.assertIn('***CASE REPORT***', html_content)
+            # TODO expand test to assert more about output HTML
+
     def test_relative_output_file_path(self):
         input_file = GeophiresInputParameters({'HTML Output File': 'foo.html'}).as_file_path()
         m = self._new_model(input_file=input_file, original_cwd=Path('/tmp/'))  # noqa: S108