Add a simple WSGI app wrapper

autoca/wsgiapp.py

+import os
+from autoca import ca
+from autoca import ca_app
+from autoca import certutil
+
+
+def create_app():
+    config = {
+        'CERTIFICATE_BITS': 2048,
+        'DATA_DIR': './data',
+        'CA_SUBJECT': 'ou=CA',
+        'CA_DIGEST': 'sha256',
+    }
+    # APP_CONFIG *must* be defined.
+    execfile(os.getenv('APP_CONFIG'), {}, config)
+    ca_instance = ca.CA(config['DATA_DIR'],
+                        certutil.parse_subject(config['CA_SUBJECT']),
+                        config['CERTIFICATE_BITS'])
+    return make_app(ca_instance)
+