Merge pull request #1870 from hackmdio/release/2.5.4

Release 2.5.4

Merge pull request #1854 from hackmdio/release/2.5.3

Release 2.5.3

Merge pull request #1850 from hackmdio/release/2.5.2

Release 2.5.2

Merge pull request #1844 from hackmdio/release/2.5.1

Release 2.5.1

Merge pull request #1835 from hackmdio/release/2.5.0

Release 2.5.0

Merge pull request #1742 from hackmdio/develop

Release 2.4.2