Installing melodic on linux mint tara (19)

edit

I installed linux mint 19 on my desktop computer (based on ubuntu 18.04) and then proceeded to installing ros melodic. First I got the problem of not finding the source of (ros tara) while running sudo apt update but this was easily solved by manually setting it to bionic. apt update runs then with no errors.

Then when I proceed with apt install ros-melodic-desktop-full I get the following error:

Reading package lists... Done   
Building dependency tree          
Reading state information... Done   
Some packages could not be installed. This may mean that you have requested
an impossible situation or if you are using the unstable distribution that
some required packages have not yet been created or been moved out of
Incoming. The following information may help to resolve the situation:
The following packages have unmet dependencies:
  ros-kinetic-desktop-full :
  Depends: ros-kinetic-desktop but it is not going to be installed
  Depends: ros-kinetic-perception but it is not going to be installed
  Depends: ros-kinetic-simulators but it is not going to be installed
  Depends: ros-kinetic-urdf-tutorial but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

here is my /etc/apt/sources.list.d/ros-latest.list

deb http://packages.ros.org/ros/ubuntu bionic main