Added a Dockerfile

The goal is to automate building of yacy docker image from latest
commits.

docker/Dockerfile

@@ -0,0 +1,33 @@
+# Base image : latest stable Debian 
+FROM debian:latest
+
+# Install needed packages
+RUN apt-get update && apt-get install -y \
+	wget \
+	default-jdk \
+	ant
+	
+# Clean apt cache
+RUN apt-get clean
+	
+# copy context : should be a YaCy git repository (remote or locally cloned)
+# context can also be obtained from extracted sources archive, but version number will be default to 1.83/9000 when building
+COPY . /opt/yacy_search_server-master
+
+# set current working dir to extracted sources directory
+WORKDIR /opt/yacy_search_server-master
+	
+# Compile with ant
+RUN ant clean compile
+
+# clean .git directory useless now
+RUN rm -rf .git
+
+# Expose port 8090
+EXPOSE 8090
+
+# Set data volume : can be used to persist yacy data and configuration
+VOLUME ["/opt/yacy_search_server-master/DATA"]
+
+# Start yacy ind debug mode (-d) to display console logs and to wait for yacy process
+CMD sh /opt/yacy_search_server-master/startYACY.sh -d