Python: Add get_version() function

This commit adds add_version() to the helpers class, which can be used
to obtain the running firmware version and build.

Libraries/Python3/pineapple/helpers/helpers.py

@@ -1,4 +1,5 @@
 import json
+from typing import Tuple
 
 
 def json_to_bytes(message) -> bytes:
@@ -14,3 +15,14 @@ def json_to_bytes(message) -> bytes:
     d = json.dumps(message)
 
     return d.encode('utf-8')
+
+
+def get_version() -> Tuple[str, str]:
+    """
+    Get the system firmware version.
+    :return: tuple containing version and build number
+    """
+
+    with open('/etc/pineapple/version', 'r') as f:
+        vers = [l.strip() for l in f.readlines()]
+        return vers[0], vers[1]