Change the base image from java to openjdk

The Java image was deprecated in favor of the OpenJDK and it will stop
being maintained at the end of the year (2016-12-31).

Author: albertogg

1.7/jdk/Dockerfile

@@ -1,4 +1,4 @@
-FROM java:8-jdk
+FROM openjdk:8-jdk
 
 RUN apt-get update && apt-get install -y libc6-dev --no-install-recommends && rm -rf /var/lib/apt/lists/*
 

1.7/jre/Dockerfile

@@ -1,4 +1,4 @@
-FROM java:8-jre
+FROM openjdk:8-jre
 
 RUN apt-get update && apt-get install -y libc6-dev --no-install-recommends && rm -rf /var/lib/apt/lists/*
 

9000/alpine-jdk/Dockerfile

@@ -1,4 +1,4 @@
-FROM java:8-jdk-alpine
+FROM openjdk:8-jdk-alpine
 
 RUN apk add --no-cache \
       bash \

9000/alpine-jre/Dockerfile

@@ -1,4 +1,4 @@
-FROM java:8-jre-alpine
+FROM openjdk:8-jre-alpine
 
 RUN apk add --no-cache \
       bash \

9000/jdk/Dockerfile

@@ -1,4 +1,4 @@
-FROM java:8-jdk
+FROM openjdk:8-jdk
 
 RUN apt-get update && apt-get install -y libc6-dev --no-install-recommends && rm -rf /var/lib/apt/lists/*
 

9000/jre/Dockerfile

@@ -1,4 +1,4 @@
-FROM java:8-jre
+FROM openjdk:8-jre
 
 RUN apt-get update && apt-get install -y libc6-dev --no-install-recommends && rm -rf /var/lib/apt/lists/*