Grid not showing data in IE11 nor Edge

[steved0x]

@riezebosch From: https://github.com/MicrosoftDocs/vsts-docs/issues/3260

Even the example (with some dummy data added) does show the grid but no data in IE11 nor Edge.

[riezebosch]

I created an issue at the SDK repository: microsoft/vss-web-extension-sdk#129

In the meantime, I swapped out the grid and replaced it with react and Office UI.