Changelog:
- PR 42: Refactoring of solinst readers
- PR 43: Undo altitude correction of level data from Solinst loggers Gold and older
- PR 44: Trim Solinst test files
- PR 45: Add support for Solinst files produced by loggers older than the Gold series
- PR 46: Setup AppVeyor and Codecov
- PR 47: Fix packaging and setup packagin on AppVeyor
- PR 49: Assert Solinst readers plot method and fix some bugs
- PR 51: Undo zero point offset for Solinst loggers of the Gold series and older