Get JitPack to build with OpenJDK 16

ensure-java-16

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+# https://github.com/jitpack/jitpack.io/issues/4355#issuecomment-744678253
+
+JV=`java -version 2>&1 >/dev/null | head -1`
+echo $JV | sed -E 's/^.*version "([^".]*)\.[^"]*".*$/\1/'
+
+if [ "$JV" != 16 ]; then
+	case "$1" in
+	install)
+		echo "installing sdkman..."
+		curl -s "https://get.sdkman.io" | bash
+		source ~/.sdkman/bin/sdkman-init.sh
+		sdk install java 16.0.1-open
+		;;
+	use)
+		echo "must source ~/.sdkman/bin/sdkman-init.sh"
+		exit 1
+		;;
+	esac
+fi

jitpack.yml

@@ -0,0 +1,8 @@
+jdk:
+  - openjdk16
+before_install:
+  - ./ensure-java-16 install
+install:
+  - if ! ./ensure-java-16 use; then source ~/.sdkman/bin/sdkman-init.sh; fi
+  - java -version
+  - ./gradlew publishToMavenLocal