Starting Ubuntu 16.04 Xenial Xerus, users can move the Unity Launcher position from its default Left to Bottom (for now, its only available Bottom). Its a good feature since many people wants to move the launcher position easily. Does not like Docky or Plank, Unity Launcher was locked on the left side. If you want to move the Launcher to bottom screen, here is how to do it.
First, install dconf editor. You can install it using command
sudo apt-get install dconf-editor
Once installed, you can open dconf-editor from Dash menu. Next, go to com | cannonical | unity | launcher
Click launcher-position and select bottom to move the launcher to the bottom. To get back, simply re select the left to move it back to left.
If you did not find launcher-position option, you must upgrade your system first.
See my video screencast on this tutorial: