inital schema

```sql                                                                                                                                                                                            
CREATE TABLE schema_migrations (                                                                                                                                                                  
    version bigint NOT NULL,                                                                                                                                                                      
    inserted_at timestamp without time zone                                                                                                                                                       
);                                                                                                                                                                                                
ALTER TABLE ONLY schema_migrations                                                                                                                                                                
    ADD CONSTRAINT schema_migrations_pkey PRIMARY KEY (version);                                                                                                                                  
                                                                                                                                                                                                  
INSERT INTO schema_migrations (version, inserted_at) VALUES (20151222140438, timezone('0', now()));                                                                                               
```