Fix import issue; Update ignore file

.gitignore

@@ -2,6 +2,8 @@
 *.swp
 *.pyc
 *.so
+*.so.*
+CMakeLists.txt
 bin
 eggs
 parts

setup.py

@@ -41,6 +41,7 @@ class hdf5:
       only. This will trigger our library search to disconsider shared
       libraries when searching.
     """
+    import os
 
     self.name = 'hdf5'
     header = 'hdf5.h'