[brew] Copy only src folders of services chosen

[sonagarajan]

Description:
Currently all contents of brew installation are copied. Modify to not to copy src folders of services that weren't chosen.

Example:
If flask, vue and mysql are chosen, then rails, kafka folders should not be copied.

Possible solutions:
Use stack array in the script to copy folders. Folder names match the service names.

Ref:
https://github.com/Stack-Box/StackBox/blob/master/brew/stackbox-brew.sh#L113