when samples are missing sparkline shouldn't crash all js
when samples are missing sparkline shouldn't crash all js

paulbellamy/scope,alban/scope,weaveworks/scope,kinvolk/scope,dilgerma/scope,kinvolk/scope,paulbellamy/scope,dilgerma/scope,dilgerma/scope,alban/scope,paulbellamy/scope,weaveworks/scope,dilgerma/scope,alban/scope,weaveworks/scope,weaveworks/scope,paulbellamy/scope,paulbellamy/scope,dilgerma/scope,alban/scope,kinvolk/scope,weaveworks/scope,weaveworks/scope,kinvolk/scope,alban/scope,kinvolk/scope,dilgerma/scope,kinvolk/scope,alban/scope,paulbellamy/scope