Bump libtool version number

Use HDF5 v2.0.0 [skip ci]

Add deploy workflow via GitHub Actions [skip travis] [skip appveyor]

Bump libtool version number

Bump date and NEWS for v1.5.26

Add test case file to distribution [ci skip]

As reported by #221

Bump date and fix NEWS for v1.5.24

Downgrade zlib to v1.2.11 at Travis CI [skip cirrus] [skip appveyor]

This is to circumvent madler/zlib#617.

Bump libtool version number

matio 1.5.21