add datacenter location awareness with pseudo-driver (cmd and file)

netbox_agent/drivers/datacenter_file.py

@@ -0,0 +1,9 @@
+import re
+
+
+def get(value, regex):
+    for line in open(value, 'r'):
+        r = re.search(regex, line)
+        if r:
+            return r.group('datacenter')
+    return None