fix(plexos_export): Added coalduns mapping to ReEDS and adding line…

… flow exporter (#55)

List of changes
---------------
- fixing an error causing some coal capacity to be dropped, 
- Added line flow as a standard output for plexos

src/r2x/defaults/plexos_reports.json

@@ -107,6 +107,30 @@
     "report_statistics": false,
     "report_summary": true
   },
+  {
+    "child_class": "Line",
+    "collection": "Lines",
+    "object_name": "base_report",
+    "parent_class": "System",
+    "phase_id": 4,
+    "property": "Flow",
+    "report_period": true,
+    "report_samples": false,
+    "report_statistics": false,
+    "report_summary": true
+  },
+  {
+    "child_class": "Line",
+    "collection": "Lines",
+    "object_name": "base_report",
+    "parent_class": "System",
+    "phase_id": 4,
+    "property": "Wheeling Cost",
+    "report_period": true,
+    "report_samples": false,
+    "report_statistics": false,
+    "report_summary": true
+  },
   {
     "child_class": "Region",
     "collection": "Regions",

src/r2x/defaults/reeds_input.json

@@ -93,6 +93,7 @@
     "coal-igcc": "ThermalStandard",
     "coal-new": "ThermalStandard",
     "coaloldscr": "ThermalStandard",
+    "coalolduns": "ThermalStandard",
     "coaluns": "ThermalStandard",
     "distpv": "RenewableNonDispatch",
     "egs_nearfield": "ThermalStandard",