update Dockerfile for v0.3.1
update Dockerfile for v0.3.1

F4-Group/herokuish,gliderlabs/herokuish,F4-Group/herokuish,gliderlabs/herokuish,F4-Group/herokuish,expa/herokuish,expa/herokuish,gliderlabs/herokuish,expa/herokuish,gliderlabs/herokuish,expa/herokuish,F4-Group/herokuish,F4-Group/herokuish,gliderlabs/herokuish,F4-Group/herokuish,F4-Group/herokuish,expa/herokuish,gliderlabs/herokuish,gliderlabs/herokuish,expa/herokuish,expa/herokuish,expa/herokuish,gliderlabs/herokuish,F4-Group/herokuish