v1.5.4

What’s Changed

• "Instant" format according to rfc1123-date1 (#238) @braginxv
• Update sbt-softwaremill-browser-test-js, ... to 2.0.12 (#236) @softwaremill-ci
• Update sbt-scala-native to 0.4.9 (#234) @softwaremill-ci
• Update sbt-scalajs, scalajs-compiler, ... to 1.12.0 (#233) @softwaremill-ci