[ADD] base_import_connector, a module to import files asynchronously
[IMP] flake8
[FIX] add connector dependency in travis
[IMP] make chunk size configurable
[IMP]base_import_connector: open attachment form with related action
[IMP] typo in docstring
[IMP] base_import_connector: add tests and fix a bug discovered in the process
[WIP] base_import_connector test suite
[IMP] test suite with hopefully good coverage

Plus fix a harmless bug revealed by the test suite.
[IMP] Improve README
[IMP] remove dead code in test suite
[IMP] remove dead code
[IMP] rename base_import_connector to base_import_async
[FIX] silence pylint, which btw discovered a genuine bug
[IMP] code style using session shortcuts
[IMP] slightly improve README
[IMP] improve test docstrings
[IMP] add comma in README
Merge pull request #3 from acsone/8.0-base_import_connector-sbi

[ADD] base_import_async, a module to import files asynchronously