Fixes #2778 - Implements HTTP/2 Push through Flask

[marimeireles]

These are the relevant changes to test the firehose lib reponsible for making push requests on Flask.
Can you please add them to Staging? So we can test if there is something wrong with my local nginx configuration.

Here is some more context to why we're doing this: #2778 (comment)

r? @miketaylr

Thanks!

[karlcow]

@marimeireles This is good work.

I wonder if there is a conflict in between HTML and HTTP. Maybe as a test we could

1. remove from the HTML template to see if it's working
2. Pass the values to the HTML template to see if it's working better.

[miketaylr]

@karlcow can you (re-)deploy this branch to staging? I tried, but apparently it doesn't like me. The fabfile is asking for a pw, that I guess I don't have (or possibly it changed)?

[karlcow]

@karlcow can you (re-)deploy this branch to staging? I tried, but apparently it doesn't like me. The fabfile is asking for a pw, that I guess I don't have (or possibly it changed)?

Probably the issue we talk about last week. I will deploy this branch. It has not been deployed yet.

[karlcow]

@miketaylr @marimeireles Firehose lib branch deployed on staging as of now.

[marimeireles]

Thanks for the help Karl and Mike.
I'll finish this PR and ask for your review once it's finished.
I still have to add the other files that have to be pushed and the code that's going to prevent the browser to fetch resources if it already has it stored.

[karlcow]

See @marimeireles' comment

[marimeireles]

r? @karlcow

[marimeireles]

Does it look good for you @karlcow ?

[karlcow]

The rest looks good to me.

thanks a lot. Once you put back the order of nosetest, I'll approve and merge.

[miketaylr]

@karlcow are we good to merge here? thanks.

[karlcow]

I will double check the config on prod and staging today. And we could probably merge it.

[karlcow]

thanks for everything @marimeireles