TST/MNT: gitignore output files from test, fix testing output to prop…

…erly check if failing_file_diffs array is []

.gitignore

@@ -1,3 +1,5 @@
+suite_scripts/test_*/
+
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]

tests/test_SuiteScripts.py

@@ -214,6 +214,7 @@ def suite_tester():
     '''
     # teardown
     # can re-enable if everyone's home dirs are getting too filled up, but not deleting avoids confusion on how to find real output files.
+    # we currently gitignore these output dirs, but to avoid issues we remove them now at start of running this script, instead of here.
     for dir in tester.expected_outcome_dirs:
         # the folders won't exist if passing b/c of missing dependencies
         if os.path.exists(dir):
@@ -222,7 +223,7 @@ def suite_tester():
 
 # this function runs after all of the pytest code (and prints will come after all pytest output)
 def ending_printout():
-    if failing_file_diffs is not None:
+    if failing_file_diffs:
         print("\n*****************************************************************")
         print("Suite-scripts tests failed b/c real output file diffs from expected file.")
         print("You can see how these output files are generated by viewing the /tests/test_SuiteScripts.py file.")