Enabled the assignment of the variable env via config

bob/bio/base/tools/command_line.py

@@ -295,7 +295,10 @@ def parse_config_file(parsers, args, args_dictionary, keywords, skips):
 
     take_from_config_or_command_line(args, config, "sub_directory",
                                      parser.get_default("sub_directory"), is_resource=False)
-
+                                     
+    take_from_config_or_command_line(args, config, "env",
+                                     parser.get_default("env"), is_resource=False)
+                                     
     skip_keywords = tuple(['skip_' + k.replace('-', '_') for k in skips])
 
     for keyword in keywords + skip_keywords + ('execute_only',):