build(deps): bump fern from 0.6.0 to 0.7.0

Fixes ActivityWatch#496

Author: wojnilowicz

aw-server/Cargo.toml

@@ -22,7 +22,7 @@ chrono = { version = "0.4", features = ["serde"] }
 appdirs = "0.2.0"
 lazy_static = "1.4"
 log = "0.4"
-fern = { version = "0.6", features = ["colored"] }
+fern = { version = "0.7", features = ["colored"] }
 toml = "0.8"
 gethostname = "0.4"
 uuid = { version = "1.3", features = ["serde", "v4"] }