Back to macos-10.15

Fix xhtml test.

Merge branch 'master' of https://github.com/iscc/iscc-cli

Bump Version to 0.9.11.

Merge pull request #48 from iscc/develop

batch command csv support

Merge pull request #46 from iscc/titusz/ghci

mac support via github ci

Update readme and bump version.

Add support for flac and opus audio formats

Merge pull request #37 from iscc/develop

Version 0.9.6

Add support for mobi7, print replica, web command support