Release 0.18 (#520)

Merge #438

438: Angle: add the normalize_zero method r=kvark a=mathstuf

This method is like `normalize` except that it normalizes to have an
absolute value of no more than `turn_div_2`.

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This is useful for making sure that an angle is no more than some offset from a target angle (e.g., implementing maximum turn rates in games).

Co-authored-by: Ben Boeckel <mathstuf@gmail.com>

Bump cargo version

Merge pull request #443 from brendanzab/v0.16

Release v0.16

Update CHANGELOG

Merge pull request #411 from brendanzab/version-bump

Bump cargo version to v0.14.1

Merge pull request #408 from brendanzab/version-bump

Bump cargo version to v0.14.0

Merge pull request #405 from ebkalderon/master

Update serialization to serde v1.0

Merge pull request #401 from brendanzab/bump-version

Bump cargo version to v0.13

Merge pull request #382 from brendanzab/version-bump

Version bump