Bump to 5.2.6

[ci skip] Bump up version to 5.2.5.

Signed-off-by: HE, Tao <[email protected]>

Bump version to 5.2.4.

Signed-off-by: Tao He <[email protected]>

Bump up hackage version to 5.2.3.

Bump for hackage

Bump for hackage

Fix cabal file

Bump for hackage

Bump for hackage

Bump for hackage