Dropping support for python versions less than 3.6

.travis.yml

@@ -3,9 +3,6 @@ os:
 dist: xenial  # for Python 3.7
 language: python
 python:
-  - "2.7"
-  - "3.4"
-  - "3.5"
   - "3.6"
   - "3.7"
   - "3.7-dev"

dictorm/__init__.py

@@ -1,4 +1,2 @@
-try:  # pragma: no cover
-    from dictorm.dictorm import *  # pragma: no cover
-except ImportError:  # pragma: no cover
-    from .dictorm import *  # pragma: no cover
+from .dictorm import *
+from .pg import Or

dictorm/dictorm.py

@@ -1,27 +1,19 @@
 """What if you could insert a Python dictionary into the database?  DictORM allows you to select/insert/update rows of a database as if they were Python Dictionaries."""
 from typing import Union, Optional, List
 
-__version__ = '3.8.5'
+__version__ = '4.0'
 
 from contextlib import contextmanager
 from itertools import chain
 from json import dumps
 from sys import modules
 
-try:  # pragma: no cover
-    from dictorm.pg import Select, Insert, Update, Delete
-    from dictorm.pg import And, Or, QueryHint
-    from dictorm.pg import Column, Comparison, Operator
-    from dictorm.sqlite import Insert as SqliteInsert
-    from dictorm.sqlite import Column as SqliteColumn
-    from dictorm.sqlite import Update as SqliteUpdate
-except ImportError:  # pragma: no cover
-    from .pg import Select, Insert, Update, Delete
-    from .pg import And, Or
-    from .pg import Column, Comparison, Operator
-    from .sqlite import Insert as SqliteInsert
-    from .sqlite import Column as SqliteColumn
-    from .sqlite import Update as SqliteUpdate
+from .pg import Select, Insert, Update, Delete
+from .pg import And, QueryHint
+from .pg import Column, Comparison, Operator
+from .sqlite import Insert as SqliteInsert
+from .sqlite import Column as SqliteColumn
+from .sqlite import Update as SqliteUpdate
 
 db_package_imported = False
 try:  # pragma: no cover
@@ -327,9 +319,6 @@ def __execute_once(self):
             sql, values = self.query.build()
             self.curs.execute(sql, values)
 
-    # for python 2.7
-    next = __next__
-
     def __len__(self) -> int:
         self.__execute_once()
         if self.db_kind == 'sqlite3':