Fixed subscriber table tests in FF (#1011)
Fixed subscriber table tests in FF (#1011)

no issue
- `ember-in-viewport` was forced to a newer version in https://github.com/TryGhost/Ghost-Admin/commit/cb46718a264daa283c92a015414bd37037a9b0c0 which has resulted in the subscriber table's infinite scroll triggering immediately in FF when testing
TryGhost/Ghost-Admin,kevinansfield/Ghost-Admin,TryGhost/Ghost-Admin,kevinansfield/Ghost-Admin