Use proper SQL types

- When recreating the table to drop a column, the correct SQL type must be
  converted by the database.
- SQLite uses BOOLEAN as base type for BOOL

issue7120
review37001002

trytond/backend/sqlite/database.py

@@ -236,6 +236,7 @@ class Database(DatabaseInterface):
     TYPES_MAPPING = {
         'DATETIME': SQLType('TIMESTAMP', 'TIMESTAMP'),
         'BIGINT': SQLType('INTEGER', 'INTEGER'),
+        'BOOL': SQLType('BOOLEAN', 'BOOLEAN'),
         }
 
     def __new__(cls, name=':memory:'):