Fix java8 compatibility (xerial#390)

* ByteBuffer.limit() compiled with JDK9+ shows  java.lang.NoSuchMethodError: java.nio.ByteBuffer.limit(I)Ljava/nio/ByteBuffer; error in JDK8
* Set --release 8 JDK option
* Do not use --release 8 option in JDK8

Add release automation workflow (xerial#384)

Releasing 1.1.8.4

Releasing 1.1.8.3

Releasing 1.1.8.2

Releasing 1.1.8.1

Releasing 1.1.8

Releasing 1.1.7.8

Releasing 1.1.7.7

Releasing 1.1.7.6