Probably the easiest way is to issue a similar command like the one below in the MacOS terminal
ln -fs "/Applications/Julia-1.0.app/Contents/Resources/julia/bin/julia" /usr/local/bin/julia
Remember I said SIMILAR, you need to double check the location of julia first in the /Application folder
This is what I have on my Mac
$ which julia
/usr/local/bin/julia
$ ls -l /usr/local/bin/julia*
lrwxr-xr-x 1 ssiew admin 62 22 Sep 2018 /usr/local/bin/julia -> /Applications/Julia-1.0.app/Contents/Resources/julia/bin/julia
lrwxr-xr-x 1 ssiew admin 62 22 Sep 2018 /usr/local/bin/julia06 -> /Applications/Julia-0.6.app/Contents/Resources/julia/bin/julia
lrwxr-xr-x 1 ssiew admin 62 22 Sep 2018 /usr/local/bin/julia07 -> /Applications/Julia-0.7.app/Contents/Resources/julia/bin/julia
$
postscript: I have not installed Julia 1.1 on my system so I have no clue where the binary for julia is located on the /Application folder for version 1.1 perhaps someone who has installed it can let you know the exact location.