feat: Add property that determines if a single complete Deployment has been defined in the product config.

Author: paulhazen

com.playeveryware.eos/Runtime/Core/Config/ProductionEnvironments.cs

@@ -50,6 +50,25 @@ public ProductionEnvironments()
             Sandboxes.SetRemovePredicate(CanSandboxBeRemoved);
         }
 
+        /// <summary>
+        /// Indicates whether there is at least one complete deployment defined.
+        /// </summary>
+        public bool IsDeploymentDefined
+        {
+            get
+            {
+                foreach (var deployment in Deployments)
+                {
+                    if (deployment.Value.IsComplete)
+                    {
+                        return true;
+                    }
+                }
+
+                return false;
+            }
+        }
+
         /// <summary>
         /// Removes a Sandbox from the Production Environment.
         /// </summary>