Prepare v0.2.0: RemoteIp.from/2 + :clients option

- Bump the minor version for the new :clients option and RemoteIp.from/2
  function. This is major functionality, but the API is backwards
  compatible, so I'm not bumping it to v1.0.0 yet.

- Bump the required Elixir/Plug versions. 1.9 is the latest, but
  versions below 1.5 aren't officially supported anymore. So I figured I
  should get with the times.

- Bump the earmark dev dependency, since old versions were causing
  issues (cf. f47a9d5).

- All the other dependencies are already up to date.

mix.exs

@@ -3,8 +3,8 @@ defmodule RemoteIp.Mixfile do
 
   def project do
     [app: :remote_ip,
-     version: "0.1.5",
-     elixir: "~> 1.3",
+     version: "0.2.0",
+     elixir: "~> 1.5",
      package: package(),
      description: description(),
      deps: deps(),
@@ -29,8 +29,8 @@ defmodule RemoteIp.Mixfile do
 
   defp deps do
     [{:combine, "~> 0.10"},
-     {:plug, "~> 1.2"},
+     {:plug, "~> 1.5"},
      {:inet_cidr, "~> 1.0"},
-     {:ex_doc, "~> 0.14", only: :dev}]
+     {:ex_doc, "~> 0.21", only: :dev}]
   end
 end

mix.lock

@@ -1,6 +1,6 @@
 %{
   "combine": {:hex, :combine, "0.10.0", "eff8224eeb56498a2af13011d142c5e7997a80c8f5b97c499f84c841032e429f", [:mix], [], "hexpm"},
-  "earmark": {:hex, :earmark, "1.4.1", "07bb382826ee8d08d575a1981f971ed41bd5d7e86b917fd012a93c51b5d28727", [:mix], [], "hexpm"},
+  "earmark": {:hex, :earmark, "1.4.2", "3aa0bd23bc4c61cf2f1e5d752d1bb470560a6f8539974f767a38923bb20e1d7f", [:mix], [], "hexpm"},
   "ex_doc": {:hex, :ex_doc, "0.21.2", "caca5bc28ed7b3bdc0b662f8afe2bee1eedb5c3cf7b322feeeb7c6ebbde089d6", [:mix], [{:earmark, "~> 1.3.3 or ~> 1.4", [hex: :earmark, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm"},
   "inet_cidr": {:hex, :inet_cidr, "1.0.4", "a05744ab7c221ca8e395c926c3919a821eb512e8f36547c062f62c4ca0cf3d6e", [:mix], [], "hexpm"},
   "makeup": {:hex, :makeup, "1.0.0", "671df94cf5a594b739ce03b0d0316aa64312cee2574b6a44becb83cd90fb05dc", [:mix], [{:nimble_parsec, "~> 0.5.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm"},