adding CountriesColumnAdder

src/HowBadIsMyBatch.ipynb

@@ -35,6 +35,8 @@
     "    exploration.drop(index=indexName, inplace=True)\n",
     "    exploration.index.rename(indexName, inplace=True)\n",
     "    exploration.drop(columns='Totals', inplace=True)\n",
+    "    for column in exploration.columns:\n",
+    "           exploration[column] = exploration[column].astype('int64')\n",
     "    return exploration"
    ]
   },