Remove dependencies on Boost.StaticAssert.

Boost.StaticAssert has been merged into Boost.Config, so replace
the dependency accordingly.

Remove dependencies on Boost.StaticAssert.

Boost.StaticAssert has been merged into Boost.Config, so replace
the dependency accordingly.

Remove Clang 3.5, 3.6 from GHA

Remove Clang 3.5, 3.6 from GHA

Update revision history

Fix GCC 4.8 Drone job to actually use 4.8

Fix GCC 4.8 Drone job to actually use 4.8

Update .drone.jsonnet

Update .drone.jsonnet

Added a release notes entry for the empty_value fix.