test for periodic maintenance along with dump

dream/simulation/JSONInputs/PeriodicMaintenance01.json

+{
+    "_class": "Dream.Simulation",
+    "edges": {
+        "0": [
+            "Q1",
+            "M1",
+            {}
+        ],
+        "1": [
+            "M1",
+            "E1",
+            {}
+        ]
+    },
+    "general": {
+        "_class": "Dream.Configuration",
+        "confidenceLevel": "0.95",
+        "maxSimTime": "20",
+        "numberOfReplications": "1",
+        "trace": "No"
+    },
+    "nodes": {
+        "Q1": {
+            "_class": "Dream.Queue",
+            "capacity": 1,
+            "left": 0.4414893617021277,
+            "name": "Q1",
+            "top": 0.40909090909090906,
+			"wip":[
+                {
+                    "_class": "Dream.Part",
+                    "id": "P1",
+                    "name": "Part1"
+                }
+			]
+        },
+        "E1": {
+            "_class": "Dream.Exit",
+            "left": 0.5,
+            "name": "Stock",
+            "top": 0.10215053763440862
+        },
+        "M1": {
+            "_class": "Dream.Machine",
+            "periodicMaintenance": {
+                "distributionType": "Fixed",
+                "MTTF": 8,
+                "MTTR": 2
+            },
+            "left": 0.5,
+            "name": "Moulding",
+            "processingTime": {
+                "distributionType": "Fixed",
+                "mean": 10
+            },
+            "top": 0.5
+        }
+    }
+}
\ No newline at end of file

dream/tests/dump/PeriodicMaintenance01.json.result

+{
+ "_class": "Dream.Simulation", 
+ "elementList": [
+  {
+   "_class": "Dream.Exit", 
+   "family": "Exit", 
+   "id": "E1", 
+   "results": {
+    "lifespan": 10.0, 
+    "takt_time": 10.0, 
+    "throughput": 1
+   }
+  }, 
+  {
+   "_class": "Dream.Machine", 
+   "family": "Server", 
+   "id": "M1", 
+   "results": {
+    "blockage_ratio": 0.0, 
+    "failure_ratio": 10.0, 
+    "waiting_ratio": 40.0, 
+    "working_ratio": 50.0
+   }
+  }, 
+  {
+   "_class": "Dream.Queue", 
+   "family": "Buffer", 
+   "id": "Q1", 
+   "results": {}
+  }
+ ], 
+ "general": {
+  "_class": "Dream.Configuration"
+ }
+}
\ No newline at end of file