Add Arista WAN devices (#1572)

* Create WAN devices

* Add mgmt interfaces

* Remove unused parameter

* Linter

* Update PSU type to match schema

* Address feedback re weight, airflow, and PSUs

* Fix linting for new files

module-types/Arista/AWE-5300-550-A-PS.yaml

@@ -0,0 +1,9 @@
+---
+manufacturer: Arista
+model: AWE-5300-550-A-PS
+part_number: AWE-5300-550-A-PS
+# airflow: front-to-rear
+power-ports:
+  - name: '{module}'
+    type: iec-60320-c16
+    maximum_draw: 550

module-types/Arista/AWE-5300-800-A-PS.yaml

@@ -0,0 +1,9 @@
+---
+manufacturer: Arista
+model: AWE-5300-800-A-PS
+part_number: AWE-5300-800-A-PS
+# airflow: front-to-rear
+power-ports:
+  - name: '{module}'
+    type: iec-60320-c16
+    maximum_draw: 800