Added detection for CoreOS devices (#8899)

DO NOT DELETE THIS TEXT

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tests/data/coreos.json

@@ -0,0 +1,35 @@
+{
+    "os": {
+        "discovery": {
+            "devices": [
+                {
+                    "sysName": "",
+                    "sysObjectID": ".1.3.6.1.4.1.8072.3.2.10",
+                    "sysDescr": "Linux coreos 4.14.48-coreos-r2 #1 SMP Thu Jun 14 08:23:03 UTC 2018 x86_64",
+                    "sysContact": null,
+                    "version": null,
+                    "hardware": "",
+                    "features": null,
+                    "location": null,
+                    "os": "coreos",
+                    "type": "server",
+                    "serial": null,
+                    "icon": "coreos.svg"
+                }
+            ]
+        },
+        "poller": "matches discovery"
+    },
+    "bgp-peers": {
+        "discovery": {
+            "devices": [
+                {
+                    "bgpLocalAs": null
+                }
+            ],
+            "bgpPeers": [],
+            "bgpPeers_cbgp": []
+        },
+        "poller": "matches discovery"
+    }
+}

tests/snmpsim/coreos.snmprec

@@ -0,0 +1,2 @@
+1.3.6.1.2.1.1.1.0|4|Linux coreos 4.14.48-coreos-r2 #1 SMP Thu Jun 14 08:23:03 UTC 2018 x86_64
+1.3.6.1.2.1.1.2.0|6|.1.3.6.1.4.1.8072.3.2.10