Using floats as interval breaks habitctl

[AiyionPrime]

Not only does habitctl not list the habits anymore, but fixing the mistake through habitctl edith is also not possible due to the same error:

$ habitctl edith
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: ParseIntError { kind: InvalidDigit }', src/main.rs:267:54
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

To reproduces the issue add a habit with a float interval, e.g.:
3.5 checkout open source projects