Running `nano` uses the old nano(2.0.6) even though nano 3.0 is installed
You don't make nano "use" anything. You run the executable you want, from the shell. Bash keeps a hash of where binaries are. If you type type nano, and it shows you the system-provided one, restart your shell or use the command hash -r to force the shell to re-hash the paths. Also, cat /etc/paths is meaningless, instead echo $PATH.