bump version, Merge branch 'unit_scale'

bump version, Merge branch 'unit_divisor'

bump version, Merge branch 'file-default-fix'

bump version, Merge branch 'nested-fix'

bump version, Merge branch 'unknown-system'

bump version, minor documentation tidy

travis git fetch tags

bump version, Merge branch 'py36'

fixes tqdm#333

bump version, Merge branch 'postfix'

bump version, Merge branch 'maxinterval-fix'