Bump toml from 0.5.8 to 0.5.9

Created by: dependabot[bot]

Bumps toml from 0.5.8 to 0.5.9.

Release notes

Sourced from toml's releases.

0.5.9

Changes:

• #373: Allow empty table keys
• #426: Fix serialization of -0.0
• #439: Make datetime structs and fields public

Commits

• 70caf40 Merge pull request #463 from ehuss/version-bump
• 63dd7f7 Bump to 0.5.9
• 499e8c4 examples: Allow dead code (#450)
• 83d787c Make datetime.rs structs and fields public #431 (#439)
• d8a9a98 Use entry api to remove a lookup in deserialisation loop (#438)
• c2a069f Upgrade to GitHub-native Dependabot (#427)
• a6420b6 Merge pull request #373 from mgsloan/allow-empty-table-keys
• 1928707 Fix serialization of -0.0. (#426)
• b141700 Merge pull request #417 from hone/patch-1
• a6e3d52 Fix comment typo
• Additional commits viewable in compare view

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