added temp dirs created by cibuildwheel to .gitignore

Author: ChrisBarker-NOAA

.gitignore

@@ -1,9 +1,14 @@
 #specific to this repo:
 
+# generated by cython
 py_gd/py_gd.c
-# docs/examples/*.png
-# docs/examples/*.gif
 
+# generated by cibuildwheel for the libs
+install/
+libgd/
+build-libgd/
+libpng/
+build-libpng/
 
 # mac files
 .DS_Store