Update num requirement from 0.2 to 0.4

[dependabot]

Updates the requirements on num to permit the latest version.

Changelog

Sourced from num's changelog.

Release 0.4.0 (2021-03-05)

• Updated num-bigint, num-complex, and num-rational to 0.4.0.
  • Updated to rand 0.8 in num-bigint and num-complex.
  • Rational is deprecated in favor of explicit Rational32 or Rational64.
• As with prior release bumps, all items exported from num-integer, num-iter, and num-traits are still semver-compatible with those exported by earlier version of num.

Release 0.3.1 (2020-11-03)

• Updated all sub-crates to their latest versions.
• Clarify the license specification as "MIT OR Apache-2.0".

Release 0.3.0 (2020-06-13)

All items exported from num-integer, num-iter, and num-traits are still semver-compatible with those exported by num 0.1 and 0.2. If you have these as public dependencies in your own crates, it is not a breaking change to move to num 0.3. However, this is not true of num-bigint, num-complex, or num-rational, as those exported items are distinct in this release.

Enhancements

• Updates to num-integer, num-iter, and num-traits are still compatible with num 0.1 and 0.2.
• The "alloc" feature enables bigint without std on Rust 1.36+.
• The "libm" feature enables Float without std in traits and complex.
• Please see the release notes of the individual sub-crates for details.

Breaking Changes

• num now requires rustc 1.31 or greater.
  • The "i128" opt-in feature was removed, now always available.
• rand support has been updated to 0.7, requiring Rust 1.32.

Contributors: @​cuviper

Release 0.2.1 (2019-01-09)

• Updated all sub-crates to their latest versions.

Contributors: @​cuviper, @​ignatenkobrain, @​jimbo1qaz

Release 0.2.0 (2018-06-29)

All items exported from num-integer, num-iter, and num-traits are still semver-compatible with those exported by num 0.1. If you have these as public dependencies in your own crates, it is not a breaking change to move to num 0.2. However, this is not true of num-bigint, num-complex, or

... (truncated)

Commits

• 644384f Merge #405
• fa3fc97 Release 0.4.0
• ba3544b Merge #401
• 89cd4b2 Release 0.3.1
• e9c345c Make licensing more explicit
• e644f82 Merge #392
• bef0050 Release 0.3.0
• 4a6873b Merge #389
• ae0e8e3 Switch CI to GitHub Actions
• 111734b Merge #385
• Additional commits viewable in compare view

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