Add GNUmakefile to the .gitignore file.

1bbdd4ed · Dave Hylands · 4ecb700f · 1bbdd4ed
Commit 1bbdd4ed authored Jul 24, 2014 by Dave Hylands
--- a/.gitignore
+++ b/.gitignore
@@ -32,3 +32,6 @@ tests/*.out
 # Python cache files
 ######################
 __pycache__/
+
+# Customized Makefile overrides
+GNUmakefile