Add migration for alpha clone character update

eos/db/migrations/upgrade20.py

@@ -0,0 +1,15 @@
+"""
+Migration 20
+
+- Adds support for alpha clones to the characters table
+"""
+
+import sqlalchemy
+
+
+def upgrade(saveddata_engine):
+    # Update characters schema to include alphaCloneID
+    try:
+        saveddata_engine.execute("SELECT alphaCloneID FROM characters LIMIT 1")
+    except sqlalchemy.exc.DatabaseError:
+        saveddata_engine.execute("ALTER TABLE characters ADD COLUMN alphaCloneID INT;")