table_exists should be called aggresively while it is false or nil, to avoid bootstrapping issues

don't test 1.9.3 in travis, it blows up randomly due to incorrect implementation of weak refs in 1.9.3

Author: SamSaffron

.travis.yml

@@ -1,6 +1,5 @@
 language: ruby
 rvm:
-  - 1.9.3
   - 2.0.0
 before_script:
   - cp config/database.yml.development-sample config/database.yml

lib/site_settings/db_provider.rb

@@ -58,7 +58,7 @@ def current_site
 
   # table is not in the db yet, initial migration, etc
   def table_exists?
-    @table_exists = ActiveRecord::Base.connection.table_exists? @model.table_name if @table_exists == nil
+    @table_exists = ActiveRecord::Base.connection.table_exists? @model.table_name unless @table_exists
     @table_exists
   end