Move templates from rice to packr

[mattstratton]

When changes are made to the event templates, they need to be recompiled. Right now that is only documented in source code at https://github.com/devopsdays/devopsdays-cli/blob/master/event/make_event_files.go#L23

	// to compile, cd to event directory and run `rice embed-go`

That's probably not amazing.

The idea is to migrate from using rice to instead use packr.

There are two main things that need to be done:

• Refactor make_event_files.go and rice-box.go to use packr instead of rice
• Update .goreleaser.yml to run packr as part of the build

[mattstratton]

@chriscoffee we might use this issue for the template re-working if you want to switch from rice; let me know and I can update the issue :)

[mattstratton]

If you look at #121 apparently, that's the ticket where I moved a bunch of stuff out of rice and put it into the .go files directly.

I'm going to rename this issue to be more about using packr instead - note that this will change how we release. The upshot of packr is that while doing local development, there is no need to run any commands to compile the templates; it is just something that happens at build time, so the build commands will need to be updated.

[mattstratton]

Of course, Mark Bates just announced a replacement for packr:
https://blog.gobuffalo.io/introducing-pkger-static-file-embedding-in-go-1ce76dc79c65

Medium

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