BackCompat fix for 2017.1 (EditorApplication.playmodeStateChanged deprecated in 2018)

unity-environment/Assets/ML-Agents/Scripts/RpcCommunicator.cs

             var result = m_client.Exchange(WrapMessage(unityOutput, 200));
             unityInput = m_client.Exchange(WrapMessage(null, 200)).UnityInput;
 #if UNITY_EDITOR
+#if UNITY_2017_2_OR_NEWER
+#else
+            EditorApplication.playmodeStateChanged += HandleOnPlayModeChanged;
+#endif
 #endif
             return result.UnityInput;
         }
         }
 
 #if UNITY_EDITOR
+#if UNITY_2017_2_OR_NEWER
         /// <summary>
         /// When the editor exits, the communicator must be closed
         /// </summary>
                 Close();
             }
         }
+#else
+        /// <summary>
+        /// When the editor exits, the communicator must be closed
+        /// </summary>
+        private void HandleOnPlayModeChanged()
+        {
+            // This method is run whenever the playmode state is changed.
+            if (!EditorApplication.isPlayingOrWillChangePlaymode)
+            {
+                Close();
+            }
+        }
+#endif
 #endif
 
     }

unity-environment/Assets/ML-Agents/Scripts/SocketCommunicator.cs

 
             unityInput = UnityMessage.Parser.ParseFrom(Receive()).UnityInput;
 #if UNITY_EDITOR
+#if UNITY_2017_2_OR_NEWER
+#else
+            EditorApplication.playmodeStateChanged += HandleOnPlayModeChanged;
+#endif
 #endif
             return initializationInput.UnityInput;
 
         }
 
 #if UNITY_EDITOR
+#if UNITY_2017_2_OR_NEWER
-        void HandleOnPlayModeChanged(PlayModeStateChange state)
+        private void HandleOnPlayModeChanged(PlayModeStateChange state)
-            if (state == PlayModeStateChange.ExitingPlayMode)
+            if (state==PlayModeStateChange.ExitingPlayMode)
+#else
+        /// <summary>
+        /// When the editor exits, the communicator must be closed
+        /// </summary>
+        private void HandleOnPlayModeChanged()
+        {
+            // This method is run whenever the playmode state is changed.
+            if (!EditorApplication.isPlayingOrWillChangePlaymode)
+            {
+                Close();
+            }
+        }
+#endif
 #endif
 
     }