Merge pull request #1649 from sharkdp/v0.18.1

bat 0.18.1

Use tempfiles for clircle tests

Bump version to 0.17.1

add new syntax test files

Updates for v0.15.4

Bump version to 0.15.3

Bump version to 0.15.2

Bump version to v0.15.1

Update CHANGELOG