Update documentation, changelog and other files [skip ci]

Author: juanpedromoreno

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## [v0.6.4](https://github.com/scala-exercises/sbt-exercise/tree/v0.6.4) (2020-08-10)
+
+[Full Changelog](https://github.com/scala-exercises/sbt-exercise/compare/v0.6.3...v0.6.4)
+
+**Merged pull requests:**
+
+- Upgrades project [\#26](https://github.com/scala-exercises/sbt-exercise/pull/26) ([juanpedromoreno](https://github.com/juanpedromoreno))
+
 ## [v0.6.3](https://github.com/scala-exercises/sbt-exercise/tree/v0.6.3) (2020-06-29)
 
 [Full Changelog](https://github.com/scala-exercises/sbt-exercise/compare/v0.6.2...v0.6.3)

CODE_OF_CONDUCT.md

@@ -11,7 +11,7 @@ appearance, body size, race, ethnicity, age, religion, nationality, or
 other such characteristics.
 
 Everyone is expected to follow the
-[Scala Code of Conduct](https://typelevel.org/code-of-conduct.html) when
+[Scala Code of Conduct](https://www.scala-lang.org/conduct/) when
 discussing the project on the available communication channels. If you
 are being harassed, please contact us immediately so that we can
 support you.