Global locals cause server to crash on second page load.
If you add global locals the server will crash on the second page load. This can be seen on the current underscore example. Here is the console output:

```
Error: yield a function, promise, generator, array, or object
    at next (/Users/cs/Desktop/koa-render/node_modules/koa/node_modules/co/index.js:107:12)
    at Object.<anonymous> (/Users/cs/Desktop/koa-render/node_modules/koa/node_modules/co/index.js:55:5)
    at next (/Users/cs/Desktop/koa-render/node_modules/koa/node_modules/co/index.js:91:21)
    at Object.<anonymous> (/Users/cs/Desktop/koa-render/node_modules/koa/node_modules/co/index.js:55:5)
    at next (/Users/cs/Desktop/koa-render/node_modules/koa/node_modules/co/index.js:91:21)
    at Object.<anonymous> (/Users/cs/Desktop/koa-render/node_modules/koa/node_modules/co/index.js:55:5)
    at Server.<anonymous> (/Users/cs/Desktop/koa-render/node_modules/koa/lib/application.js:105:8)
    at Server.EventEmitter.emit (events.js:101:17)
    at HTTPParser.parserOnIncoming [as onIncoming] (_http_server.js:505:12)
    at HTTPParser.parserOnHeadersComplete (_http_common.js:111:23)

/Users/cs/Desktop/koa-render/node_modules/co-views/node_modules/co-render/node_modules/consolidate/lib/consolidate.js:143
          if (err) return fn(err);
                          ^
TypeError: string is not a function
    at /Users/cs/Desktop/koa-render/node_modules/co-views/node_modules/co-render/node_modules/consolidate/lib/consolidate.js:143:27
    at /Users/cs/Desktop/koa-render/node_modules/co-views/node_modules/co-render/node_modules/consolidate/lib/consolidate.js:95:21
    at fs.js:195:20
    at Object.oncomplete (fs.js:97:15)
```
