[license] Change license from MIT to UCL

For legal reasons, official Unity packages must be under the UCL
license. The only contribution made by someone outside of Unity was for
a typo in the documentation.

Author: MightyCreak

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Changed
 
 - Updated the Yamato CI configuration
+- Moved from MIT to UCL license
 
 ## [0.1.0] - 2018-12-20
 

LICENSE

@@ -0,0 +1,5 @@
+PlayableGraph Visualizer copyright © 2019 Unity Technologies ApS
+
+Licensed under the Unity Companion License for Unity-dependent projects -- see [Unity Companion License](http://www.unity3d.com/legal/licenses/Unity_Companion_License).
+
+Unless expressly provided otherwise, the Software under this license is made available strictly on an “AS IS” BASIS WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. Please review the license for details on these and other terms and conditions.