use why3 api

.gitlab-ci.yml

headers/header_spec.txt

nix/default.nix

src/libraries/utils/task.ml

src/libraries/utils/task.mli

src/plugins/qed/logic.ml

src/plugins/qed/term.ml

src/plugins/qed/term.mli

src/plugins/wp/.gitignore

src/plugins/wp/.merlin

src/plugins/wp/Definitions.ml

src/plugins/wp/Definitions.mli

src/plugins/wp/GuiConfig.ml

src/plugins/wp/GuiConfig.mli

src/plugins/wp/GuiGoal.ml

src/plugins/wp/GuiList.ml

src/plugins/wp/GuiNavigator.ml

src/plugins/wp/GuiPanel.ml

src/plugins/wp/GuiPanel.mli

src/plugins/wp/GuiProver.ml