Paste in Terminal to create a blank file :
sudo gedit /usr/local/bin/skype
(that if gedit is your text editor)
There, paste the following:
save and close
Now to make the file executable, copy and paste the following line into Terminal.
sudo chmod a+x /usr/local/bin/skype
thanks to this source, including the change suggested by JuliusP0pp in his comment there