environments 1.6.2 breaks the installation of eggs which depend on it

[Mario Domenech Goulart]

Attempting to install environments with recent CHICKENs break with

Error: Sorry, but CHICKEN 4.7.4 and later is not supported anymore

This ​breaks the installation of eggs which depend on environments:

• ​http://salmonella-linux-x86.call-cc.org/chicken-4-debugbuild/gcc/linux/x86/2018/08/24/salmonella-report/install/uri-dispatch.html

• ​http://salmonella-linux-x86.call-cc.org/chicken-4-debugbuild/gcc/linux/x86/2018/08/24/salmonella-report/install/couchdb-view-server.html

I don't know if these eggs actually hard-depend on environments to work. In case they do, I think they should be moved to the "obsolete" category as well.