Deprecate uri_template package on pub

[Scorpiion]

Based on this it seems like the old package should be deprecated with a deprecated note on pub:
f3cdaf4

Package in question:
https://pub.dartlang.org/packages/uri_template

I would like to suggest that uri_template was deprecated similar to how web_ui have been:
https://pub.dartlang.org/packages/web_ui

What do you think @justinfagnani ? It can be a little confusing for new users as it is now.

[sethladd]

Thanks for the suggestion!