Finam-export

Fixed
- TICKS data download in some cases might miss some days (https://github.com/ffeast/finam-export/issues/16)

Fixed
- version in setup.py

Added
- automatic request split for long intervals (https://github.com/ffeast/finam-export/issues/4)
Changed
- from now on everything needs to be exported from finam package (instead of finam.export and others)
- automatic retries when hitting the error "Система уже обрабатывает Ваш запрос. Дождитесь окончания обработки."
Fixed
- download from time intervals that don't include any trading sessions (i.e. 2018-01-01) is now safe and would result in empty data file instead of an exception

Changed
- dropped python2.x support as the newest pandas doesn't support it

Added
- --ext option support in ./scripts/finam-download.py to enable configuration of the resulting files
Changed
- date/time export format changed to separate columns <DATE> and <TIME> instead of a datetime in a single <DATE> field to make it compatible with tslab and other software
- switched logging mode to .INFO to get rid of annoying debug lines
- unpinned urltools dependency as the previous version doesn't exist
- upgraded dependencies to modern versions

Added
- new market CURRENCIES_WORLD=5 (https://github.com/ffeast/finam-export/pull/9)
Changed
- finam-downloader.py would take into account market code even if contracts are specified