Fix Docker issue

[alejandro-kid]

I did three changes:

• Change th way of build the container.
• Change script to generate application.yml:

  Explanation: The awk command iterates through each element of a list and executes its instructions, in each iteration it checks that the corresponding environment variable contains information. Since it is impossible to declare a valid environment variable for the system with the following structure 'Cenit::Admin:default_uri', it is decided to create it from one that is valid and eliminate the other environment variable declared in the file, to be provided by the system globally.

• It necesary when the container run, declare a variable called: ADMIN_UI.

[sanchojaf]

keep this file like was before and add this line at the end

[alejandro-kid]

• Delete application.docker.yml: Now the config/application.yml will be create inline using an script when the container run. For this purpose need declared two environment variables HOMEPAGE and CENIT_UI.

  Note: The main conclusion of all my test is that in application.yml need to have both env variables (HOMEPAGE and Cenit::Admin:default_uri), even if HOMEPAGE is not in it, the platform will not redirect correctly.

• Update docker-compose.yml: Here I deleted the configuration of NGINX. Docker compose is not for productions, so dont have sense configure NGINX, i remove this element to do the file more simple.
• Enable build container in developer branch and redefine tags of container: I think that the best way to resolve a bug is knowin where is it. For this reason I configured a system of tags, the tags of master branch will be latest and a short sha (the first 7 numbers), because with the current tag when a new container is pushed override the previusly. And in developer branch the container will have a tag as following: develop-${SHA}