PUT must drop/recreate item in the same transaction

[goneri]

So far, PUT was calling replace() to drop, commit, recreate the item. By doing this, we can get the situation where the initial drop break the foreign keys of the other tables. Instead, if we do the drop/recreate in the same transaction, the constraint engine will ignore the unstable situation.

This commit extend the code coverage:

• enable SQLite FK constrain check. We use 'pragma foreign_keys=on' to do that.
• create a new notes table with a FK on the people._id key.

See: https://www.sqlite.org/pragma.html

[goneri]

coveralls is on crack again :)

[mmiz]

Looks like this fixes the situation i mentioned here: https://github.com/RedTurtle/eve-sqlalchemy/issues/64

[goneri]

@mmiz, thanks for the feedback.

[goneri]

@amleczko, can you please have a look at the PR?

[amleczko]

I will check it next week

[goneri]

@amleczko for the record, I use this branch daily since august with without any problem.

[amleczko]

right @goneri, thanks

[goneri]

thanks @amleczko.

[amleczko]

I have merged it to develop branch and will release soon.