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/fugue/applywarp/feedsRun

 #!/usr/bin/env fslpython
 
-
+import				   os
 import                             shlex
 import subprocess           as     sp
 import numpy                as     np
@@ -78,4 +78,5 @@ def test_applywarp_uses_sqform_correctly():
 
 
 if __name__ == '__main__':
+    os.chdir(sys.argv[2])
     test_applywarp_uses_sqform_correctly()