v0.5.0-beta.8

Changelog:

• New features:
  • Add zn_config_from_file() operations
  • Add zn_config_to_str() operations
• Other changes:
  • Bump dependency to zenoh 0.5.0-beta.8 (see its Changelog)
  • Examples call zn_init_logger() to provide logs when $RUST_LOG env var is set.

Available on:

• https://download.eclipse.org/zenoh/zenoh-c/0.5.0-beta.8/