[slog-config] failed to select a version for `toml`

[TheAifam5]

Hey, I found an issue with the slog-config crate. I'm new in Rust so I don't really know if that is on my side.

Environment: rustup 1.18.3 (2019-05-23) rustc 1.37.0 (eae3437df 2019-08-13)

truckly-shared/Cargo.toml:

itertools = "0.8"
rayon = "1.1"
libloading = "0.5"
serde = { version = "1.0", features = ["derive"] }
bincode = "1.1"
slog = { version = "2.5", features = ["nested-values", "dynamic-keys"] }
sloggers = "0.3"
slog-journald = "2.0"
slog-atomic = "3.0"
slog-config = "0.4"
slog-scope = "4.1"
slog-async = "2.3"
tokio = "0.1"

Log:

error: failed to select a version for `toml`.
    ... required by package `slog-config v0.4.0`
    ... which is depended on by `truckly-shared v0.1.0 (/home/theaifam5/Documents/Projects/TheAifam5/truckly/truckly-shared)`
    ... which is depended on by `prism v0.1.0 (/home/theaifam5/Documents/Projects/TheAifam5/truckly/prism)`
    ... which is depended on by `truckly v0.1.0 (/home/theaifam5/Documents/Projects/TheAifam5/truckly/truckly)`
versions that meet the requirements `^0.4` are: 0.4.10, 0.4.9, 0.4.8, 0.4.7, 0.4.6, 0.4.5, 0.4.4, 0.4.3, 0.4.2, 0.4.1, 0.4.0

the package `slog-config` depends on `toml`, with features: `serde` but `toml` does not have these features.
 It has a required dependency with that name, but only optional dependencies can be used as features.


all possible versions conflict with previously selected packages.

  previously selected package `toml v0.4.10`
    ... which is depended on by `slog-config v0.4.0`
    ... which is depended on by `truckly-shared v0.1.0 (/home/theaifam5/Documents/Projects/TheAifam5/truckly/truckly-shared)`
    ... which is depended on by `prism v0.1.0 (/home/theaifam5/Documents/Projects/TheAifam5/truckly/prism)`
    ... which is depended on by `truckly v0.1.0 (/home/theaifam5/Documents/Projects/TheAifam5/truckly/truckly)`

failed to select a version for `toml` which could resolve this conflict

Regards, TheAifam5