tests 2000 and 2001 updated

use damask_tools to check whether DAMASK_ROOT is set

lib/damask_tools.py

@@ -0,0 +1,9 @@
+class DAMASK_TOOLS():
+    import os,string
+    def check_env(self):
+        import os
+        if os.getenv('DAMASK_ROOT') is None:
+          print('No DAMASK_ROOT environment variable, did you run DAMASK/installation/setup_shellrc?')
+          sys.exit(1)
+        else:
+          return True