Dockerfile error

[gokul-lucifer]

Hi, I'm trying to build a docker image with your dockerfile, while installing dependency mysqlclient==2.0.1 in requirement.txt throws error as,

**Complete output from command python setup.py egg_info:

/bin/sh: mysql_config: not found
/bin/sh: mariadb_config: not found
/bin/sh: mysql_config: not found

Traceback(most recent call last):
File "<string>" line 1, in <module>
File "/tmp/pip-install-q8005th1/mysqlclient/setup.py", line 15, in <module>
     metadata, options = get_config
File "/tmp/pip-install-98005th1/mysqlclient/setup_posix.py", line 65, in get_config
     libs = mysql_config("libs")
File "/tmp/pip-install-98005th1/mysqlclient/setup_posix.py", line 31, in mysql_config
     raise OSError("{} not found".Format(_mysql_config_path))
OSError: mysql_config not found
 -------------------------------------------------------------------------------
Command "python setup.py egg_trfo" failed with error code i tn /tmp/ptp-install-qasasth1/mysql.client/
You are using pip version 18.1., however version 28.2.4 is available.
You should consider upgrading via the pip install upgrade pip' command.
The command '/bin/sh -c pip3 install --user --no-cache-dir -r requirements.txt' returned a non-zero code: 1**

[glaslos]

Will be fixed in #522