Ubuntu: Add Zulip link to the binrary.

Zulip can't be run from the terminal because we were not
linking the binary to the bin. The electron-builder used to support
this by default but we as we added the afterInstall
script it got removed.

More info -
https://github.com/electron-userland/electron-builder/issues/2682,
https://github.com/electron-userland/electron-builder/issues/2689

Fixes #444.

scripts/debian-add-repo.sh

@@ -2,6 +2,10 @@
 
 # This script runs when user install the debian package
 
+# Link to the binary
+ln -sf '/opt/${productFilename}/${executable}' '/usr/local/bin/${executable}';
+echo 'Successfully added /opt/${productFilename}/${executable} to /usr/local/bin/${executable}'
+
 # Install apt repository source list if it does not exist
 if ! grep ^ /etc/apt/sources.list /etc/apt/sources.list.d/* | grep zulip.list; then
     sudo apt-key adv --keyserver pool.sks-keyservers.net --recv 69AD12704E71A4803DCA3A682424BE5AE9BD10D9

scripts/debian-uninstaller.sh

@@ -28,4 +28,8 @@ appDirectory=/home/$getSudoUser/.config/Zulip/;
 
 if [ -d $appDirectory ]; then
     sudo rm -rf $appDirectory;
-fi
+fi
+
+# Delete the link to the binary
+echo 'Removing binary link'
+sudo rm -f '/usr/local/bin/${executable}';