some issues and solutions

[Sheryx00]

I want to contribute with some changes what I needed to make it flow good:

• In php7-fpm/Dockfile:
  Step 3: add apt-get update && before to install the packages, so it apt-get can find their.
  Step 7: add zlib1g-dev library to the list

• In nginx/Dockfile:
  Step 3: add apt-get update && before install the packages too

• In cli/Dockfile:
  Step 3: change mysql-client for mariadb-client