Build error: feature `generators` renamed to `coroutines`

[Mart-Bogdan]

Build log:

error[E0557]: feature has been removed
  --> /home/bbbb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/gen-iter-0.3.0/src/lib.rs:60:12
   |
60 | #![feature(generators, generator_trait)]
   |            ^^^^^^^^^^ feature has been removed
   |
   = note: renamed to `coroutines`