Feature: import cycle warnings

[sanderhahn]

Would be nice to get lint results for cyclic (static) import dependencies, to stimulate writing code with layered responsibilities. Current lint rules works on a file basis, however the dependency information is available in the cache and using the deno info command.

Made a prototype based upon the deno info --json output: https://github.com/sanderhahn/deno_cycle

https://en.wikipedia.org/wiki/Circular_dependency

Can help to implement this if this is considered a good feature to have.

[bartlomieju]

https://github.com/denoland/deno_lint/issues/454 is required to implement this feature