v2.0.0-RC6-27

Changes

• Add support for the arm and aarch64 JVM architectures in the java and java-home commands (#1849, thanks to @matsluni)
• Build native launchers with GraalVM 20.1.0 Java 11 (former coursier versions used GraalVM 19.3.1 Java 8)
• Add --jvm-index option to the java / java-home / setup commands, allowing to pass a custom JVM index URL, also accepting aliases such as jabba (current default) and cs (supporting less JVM flavors, but more up-to-date)

Other

• coursier now uses GitHub actions for its CI, rather than Travis CI and Appveyor
• The switch to GraalVM 20.1.0 and GitHub actions fixes the generation of native launchers on the CI, which should be shipped as GitHub release assets again (which was broken in 2.0.0-RC6-25 and 2.0.0-RC6-26)