To istall libgtk-3-dev you may need first to issue a "sudo apt upgrade" command from a shell.
Cannot install on Linux Mint Rosa 17.3. The following packages have unmet dependencies: libgtk-3-dev : Depends: libgtk-3-0 (= 3.10.8~8+qiana) but 3.10.8-0ubuntu1.6 is to be installed Depends: gir1.2-gtk-3.0 (= 3.10.8~8+qiana) but 3.10.8-0ubuntu1.6 is to be installed E: Unable to correct problems, you have held broken packages.