Docker 镜像错误:“/bin/sh: 1: [python,: not found"

I'm building a new Docker image based on the standard Ubuntu 14.04 image.

这是我的 Dockerfile:

FROM ubuntu:14.04
RUN apt-get update -y
RUN apt-get install -y nginx git python-setuptools python-dev
RUN easy_install pip
ADD . /code
WORKDIR /code
RUN pip install -r requirements.txt # only 'django' for now
ENV projectname myproject
EXPOSE 80 8000
WORKDIR ${projectname}
CMD ['python', 'manage.py', 'runserver', '0.0.0.0:80']

当我尝试运行此映像时，我收到此错误...