Updated environment_specclassify.yml. Use SPDX license identifier and set all...

Updated environment_specclassify.yml. Use SPDX license identifier and set all files to GLP3+ to be consistent with license headers in the source files. Excluded tests from being installed via 'pip install'. Set development status to 'Alpha'. Updated version info.

Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>