Merge pull request #332 from Unity-Technologies/Branch_SkyRenderTextureHash

Added code to update Sky render texture hash so that GI bakes correctly. Code is commented until new API reaches graphics/srp

Assets/ScriptableRenderPipeline/HDRenderPipeline/Sky/SkyManager.cs

                         m_UpdatedFramesRequired--;
                         m_SkyParametersHash = skySettings.GetHash();
                         m_CurrentUpdateTime = 0.0f;
+//#if UNITY_EDITOR
+//                        m_SkyboxCubemapRT.imageContentsHash = new Hash128((uint)skySettings.GetHash(), 0, 0, 0);
+//#endif
                     }
                 }
             }