Log Message:
time/heliocron: update to 0.8.1

[v0.8.1] - 2022-08-01
Added
   add --watch and --json to an overall much enhanced poll subcommand.

[v0.8.0] - 2022-07-31
Added
   poll subcommand - when executed, will return whether it is day, night or
    twilight (#54).

Fixed
   More time zone errors... more tests added to prove correctness (#53).
   Errors when running integration tests using rust-cross (#58)

Changed
   Switched from pseudo-decimal degrees (e.g. "5.1N") to actual decimal
    degrees (e.g. 5.1) for coordinates (#56).
   Refactored Github Actions workflows

[v0.7.0] - 2022-06-12
Fixed
   Fixed handling of time zones so that they are now implemented properly (#41).

Changed
   Migrated from old version of structopt to clap for command line argument
    parsing.

Removed
   --date-format flag has been removed as it adds additional complexity when
    validating command line args for no real benefit.

[v0.6.1] - 2022-06-11

Cut a new release specifically for crates.io to bump tokio-walltime to v0.1.2.
Previous versions of tokio-walltime failed to compile on the Raspberry Pi
architectures. v0.6.0 of heliocron has been yanked from crates.io.