ASF Tools v0.7.1

Added

• A description of the asf_tools.watermasking sub-package has been added to the asf_tools README
• Installation instructions for osmium-tool have been added to the asf_tools.watermasking README

Fixed

• osmium-tool dependency handling. Because osmium-tool is not distributed on PyPI and thus is not installed when pip installing asf_tools, asf_tools will now raise an ImportError when osmium-tool is missing that provides installation instructions. Note: osmium-tool is distributed on conda-forge and will be included when conda installing asf_tools.