committing changes in /etc made by "/usr/bin/apt install -y opam"

committing changes in /etc made by "/usr/bin/apt install -y opam"

Package changes:
+darcs 2.14.2-2build2 amd64
+libglpk40 4.65-2 amd64
+libncurses-dev 6.2-0ubuntu2 amd64
+libncurses5-dev 6.2-0ubuntu2 amd64
+mercurial 5.3.1-1ubuntu1 amd64
+mercurial-common 5.3.1-1ubuntu1 all
+ocaml 4.08.1-8 amd64
+ocaml-base 4.08.1-8 amd64
+ocaml-base-nox 4.08.1-8 amd64
+ocaml-compiler-libs 4.08.1-8 amd64
+ocaml-interp 4.08.1-8 amd64
+ocaml-man 4.08.1-8 all
+ocaml-nox 4.08.1-8 amd64
+opam 2.0.5-1ubuntu1 amd64
+opam-doc 2.0.5-1ubuntu1 all
+opam-installer 2.0.5-1ubuntu1 amd64