Python 3.6 support: sqlite3.OperationalError: Safety level may not be changed inside a transaction

[bit]

fails in python3.6 with

Exception in thread Thread-2:
Traceback (most recent call last):
File "/usr/lib/python3.6/threading.py", line 916, in _bootstrap_inner
self.run()
File ".../site-packages/sqlitedict.py", line 371, in run
cursor.execute('PRAGMA synchronous=OFF')
sqlite3.OperationalError: Safety level may not be changed inside a transaction

[tmylk]

How can this be reproduced? It doesn't come up in Travis Python 3.6 tests

[bit]

creating a new instance with autocommit=False triggers this here:

test = SqliteDict(autocommit=False)

[bit]

Looks like travis still does not fail.
Even without a new test, make test-all fails here on Arch Linux and Debian/unstable with python3.6 and sqlite 3.16.2

[tmylk]

Let's check sqlite version used in Travis in #62

[tmylk]

Hmm the sqlite version in travis is really old.

[bit]

Also fails with Ubuntu 17.04 (sqlite 3.15.2).
Here a Dockerfile to test with Ubuntu 17.04, possibly something like that can be added to travis

[bit]

Also fails in Ubuntu 16.10 (sqlite 3.14.1 / Python 3.6)