Release 0.4.0

What's Changed

• feat: add assert_that for custom matchers by @DamianReeves in #43
• feat: add navigation and the all block by @DamianReeves in #44
• feat: generalize expect_call and chain on call results by @DamianReeves in #45
• feat: add collection matchers for order, quantity and uniqueness by @DamianReeves in #46
• feat: add map matchers and a map-aware diff by @DamianReeves in #47
• feat: add string matchers and point at the first string difference by @DamianReeves in #48
• feat: add sign, range and floating-point matchers by @DamianReeves in #49
• feat: add because, to_be_one_of, to_be_in and Char matchers by @DamianReeves in #50
• feat: add Json matchers and show Bytes as a hex dump by @DamianReeves in #51
• feat: mark changed characters in diffs and generate a matcher catalog by @DamianReeves in #52
• chore: release 0.4.0 by @DamianReeves in #53

Full Changelog: v0.3.0...v0.4.0