v1.0.0

CHANGES:

• split opam package into two separate ones: a core
  arp package and the arp-mirage implementation
  for MirageOS that has more dependencies. This
  eliminates the use of depopts that was done previously
  to build the Mirage layer. (#7 @avsm)

• port build system to Dune (#7 @avsm). The make coverage
  and make bench targets will do the job of the previous
  topkg targets for those.

• minor fixes to ocamldoc comments to be compatible with
  odoc.

• use mirage-random and mirage-random-test instead of a
  nocrypto dependency in tests and bench (#7 @hannesm)

• import tests from mirage-tcpip (#8 @hannesm)

• depend on the ethernet opam package, no longer provided
  by tcpip >3.7.0 (#9 @hannesm)