add role observation one hots

Project/Assets/ML-Agents/Examples/CubeWars/Prefabs/SmallAgent.prefab

   m_Name: 
   m_EditorClassIdentifier: 
   m_BrainParameters:
-    VectorObservationSize: 4
+    VectorObservationSize: 7
     NumStackedVectorObservations: 2
     m_ActionSpec:
       m_NumContinuousActions: 3
   MaxStep: 3000
   area: {fileID: 0}
   largeAgent: {fileID: 0}
-  turnSpeed: 300
-  moveSpeed: 6
+  role: 0
 --- !u!1 &8083875348725975067
 GameObject:
   m_ObjectHideFlags: 0

Project/Assets/ML-Agents/Examples/CubeWars/Scripts/SmallCubeAgent.cs

     }
 
     public Role role;
+    float[] m_RoleObs;
+        m_RoleObs = new float[3];
+            m_RoleObs[0] = 1f;
             m_HitPoints = .7f;
             m_Damage = 0f;
             m_Heal = .7f;
         }
         else if (role == Role.DPS)
         {
+            m_RoleObs[1] = 1f;
             m_HitPoints = .6f;
             m_Damage = .05f;
             m_Heal = 0f;
         }
         else if (role == Role.Tank)
         {
+            m_RoleObs[2] = 1f;
             m_HitPoints = 1f;
             m_Damage = .02f;
             m_Heal = .2f;
         Vector3 dirToSelf = transform.position - m_LargeAgent.transform.position;
         float angle = Vector3.Dot(m_LargeAgent.transform.forward.normalized, dirToSelf.normalized);
         sensor.AddObservation(angle);
+        sensor.AddObservation(m_RoleObs);
     }
 
     public Color32 ToColor(int hexVal)