Update consumers of IntegrationTesting after #996

[analogrelay]

We need to update consumers of IntegrationTesting after merging #996. There is a breaking change in 0.4.0 and while 0.3.0 is still on the feed, it will fall off soon. Also we want to use the new logging ;)

Just tracking the many PRs for this here. Will close when they're all merged.

• react to aspnet/Hosting#996 MusicStore#769
• react to aspnet/Hosting#996 Entropy#217
• react to aspnet/Hosting#996 IISIntegration#349
• react to aspnet/Hosting#996 ServerTests#67
• Verify test build ran with all these changes

I think that's all of them. /cc @Tratcher @natemcmaster

[analogrelay]

Reminder to unpin 0.3.0 of IntegrationTesting when this closes. /cc @pranavkm @Eilon

[analogrelay]

@pranavkm The package can be unpinned now!