Unknown "ivory_google_map" function

Hello,

i've followed the instruction and installed 
```
egeloen/google-map v.2.0.2,
egeloen/serialiser v1.0.0
guzzlehttp/guzzle v6.3.3,
php-http/message v.1.6.0
```

I'm trying to render map in twig using: 
`{{ ivory_google_map(map) }}`

But, i'm getting unknown function error.

Did i miss something?