Conditional schema dump

This adds a configuration option to disable dumping views to the schema, also includes a railtie to set the config.

```
Spectacles.configure do |config|
  config.enable_schema_dump = false
end
```

or

```
Application < Rails::Application
  config.spectacles.enable_schema_dump = false
end 
```

I also added sorting to the views when they are dumped to the schema so they should appear in the same order now.