This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
```
change_column :topic_views, :ip_address, :inet, null: true
```
translates to
```
"ALTER TABLE \"topic_views\" ALTER COLUMN \"ip_address\" TYPE inet"
```
which locks the whole table while the migration is taking place.
David Taylor
Sam Saffron
Guo Xiang Tan
riking