Deploy to elastic beanstalk config

This is my config :

.ebextensions/01run.config

packages:
  yum:
    libxml2: []
    libxml2-devel: []
    libxslt: []
    libxslt-devel: []
    postgresql93-devel: []
    python-devel: []
    python27-devel: []

When deploy to EB , There is error , Please help me!! What else should I install ?? Thank you

Error: pg_config executable not found.

Please add the directory containing pg_config to the PATH
or specify the full executable path with the option:

    python setup.py build_ext --pg-config /path/to/pg_config build ...

or with the pg_config option in 'setup.cfg'.
Complete output from command python setup.py egg_info:
running egg_info