BF: feedsRun writing to test directory, not output directory

unit_tests/avwutils/fix_orient currently writes its files to the test directory and not the output directory. This fix will chdir before each test is called - this only needs to be done once, but by placing in the main try block the script will throw if the chdir fails for any reason.

unit_tests/avwutils/fix_orient/feedsRun

@@ -68,6 +68,7 @@ above assumptions:
 
 import numpy      as np
 import nibabel    as nib
+import               os
 import subprocess as sp
 import               shlex
 import               sys
@@ -154,6 +155,7 @@ if __name__ == '__main__':
     result = 0
     for test in tests:
         try:
+            os.chdir(sys.argv[2])
             test()
             print(f'\nTest {test.__name__} PASSED')
         except Exception as e: