Issue #112 Allow running container under different user to match jenkins home volumes

Put copy_reference_file.log so container starts with different user id
diff --git a/Dockerfile b/Dockerfile
index d5b2da5..4b8f4fb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -39,8 +39,7 @@
 # will be used by attached slave agents:
 EXPOSE 50000
 
-ENV COPY_REFERENCE_FILE_LOG /var/log/copy_reference_file.log
-RUN touch $COPY_REFERENCE_FILE_LOG && chown jenkins.jenkins $COPY_REFERENCE_FILE_LOG
+ENV COPY_REFERENCE_FILE_LOG $JENKINS_HOME/copy_reference_file.log
 
 USER jenkins
 
diff --git a/README.md b/README.md
index 1f559c9..0ded947 100644
--- a/README.md
+++ b/README.md
@@ -22,8 +22,8 @@
 docker run -p 8080:8080 -p 50000:50000 -v /your/home:/var/jenkins_home jenkins
 ```
 
-This will store the jenkins data in /your/home on the host.
-Ensure that /your/home is accessible by the jenkins user in container (jenkins user - uid 1000).
+This will store the jenkins data in `/your/home` on the host.
+Ensure that `/your/home` is accessible by the jenkins user in container (jenkins user - uid 1000) or use `-u some_other_user` parameter with `docker run`.
 
 
 You can also use a volume container: