Merge pull request #29 from Seshat-Global-History-Databank/avoid-dupl…

…icates

Ensure get_all function doesnt add the same API result more than once

seshat_api/base_model.py

@@ -298,7 +298,9 @@ def get_all(self):
             results = response.get('results', [])
             if not results:
                 break
-            all_results.extend(results)
+            for result in results:
+                if result['id'] not in [r['id'] for r in all_results]:
+                    all_results.append(result)
             page += 1
 
         return all_results