update readme

README.md

@@ -7,7 +7,7 @@
 - Bundler
 - PostgreSQL or MySQL
 
-## Installation
+## Installation (production)
 
 ### Database
 
@@ -24,6 +24,8 @@ Try connecting to the database:
 
 #### MySQL
 
+**Note:** We do not test for MySQL.  Caveat emptor.
+
     $ mysql -u root -p
     # change 'hack me' in the command below to a real password
     mysql> CREATE USER 'justask'@'localhost' IDENTIFIED BY 'hack me';