Update Java 8 instructions for MacOS

[ianmilligan1]

Java 8 no longer installs properly using brew once you're on MacOS Catalina. I worked with @sarahcmct to get it set up on her system, so we should tweak the README to point to the new way to get this up and running.

[SamFritz]

I'm still running High Sierra (version 10.13.6) and had an issue with brew cask install java8, was able to get things running using the following command:

brew cask install adoptopenjdk/openjdk/adoptopenjdk8

Some Github discussions that helped when I ran into this issue:

• Java8 not working anymore #7253
• Fix Java 1.8 requirement caveats
  #6035: identified that "java8 cask no longer exists"
• Further discussion of Endorse AdoptOpenJDK instead of Oracle OpenJDK #6040

I think further testing would be good on this; happy to nuke my AUT version to start fresh so we can update documentation along with methods @sarahcmct and @ianmilligan1 found helpful to get up and running.

[ianmilligan1]

I guess Sarah isn't on GitHub. This is great, thanks @SamFritz. I think the issue with Catalina is that they're not letting brew install any "unsigned" software anymore which also includes Java.

My recommendation might be to just encourage them to download directly from Java here, and then manually set their JAVA_HOME. We can have both in parallel but as more people end up on Catalina brew simply won't work anymore I gather.

[ruebot]

I'd suggest OpenJDK if possible. We have no hard dependencies on Oracle Java, so more than happy to not point folks to Oracle.

[ianmilligan1]

How about https://adoptopenjdk.net/ as a starting point? The installation instructions are actually decent. Seems to be a bit of a scavenger hunt to find a MacOS version of Java 8 on the main OpenJDK site.

[ruebot]

Oh, @SamFritz has it in her initial comment brew cask install adoptopenjdk/openjdk/adoptopenjdk8

[ianmilligan1]

I’m not sure if that’s working on Catalina anymore (Sam is still on High Sierra). I can investigate tomorrow.

[ruebot]

Ohhhhhhhhh