Install new NANO (2.4) using BREW but still uses old versions (symbolic link not created?)

I installed NANO 2.4 but my OS X is still using 2.0. I beleive its something to do with the symbolic link that wasn't created.

I first tapped the homebrew/dupes so i could brew install nano

~  brew tap homebrew/dupes
==> Tapping homebrew/dupes

~  brew install nano
==> Installing nano from homebrew/homebrew-dupes

If I do a

which nano

I get

/usr/bin/nano

but the brew installed in the directory below and I have it confirmed as 2.4 by running the program directlt from here

/usr/local/Cellar/nano/2.4.2_1/bin

I think a symbolic link wasn't created becasue nano is already included with mac os x, is it safe to override it ?

I got the following warning on the brew install from

==> Downloading https://ftp.gnu.org/gnu/ncurses/ncurses-6.0.tar.gz
######################################################################## 100.0%
==> ./configure --prefix=/usr/local/Cellar/ncurses/6.0 --enable-pc-files --enable
==> make install
==> Caveats This formula is keg-only, which means it was not symlinked into /usr/local.

OS X already provides this software and installing another version in
parallel can cause all kinds of trouble.

Generally there are no consequences of this for you. If you build your
own software and it requires this formula, you'll need to add to your
build variables:

    LDFLAGS:  -L/usr/local/opt/ncurses/lib
    CPPFLAGS: -I/usr/local/opt/ncurses/include

==> Summary ?  /usr/local/Cellar/ncurses/6.0: 1970 files, 21M, built in 114 seconds