Deprecate :protocol in favour of :protocols

Follow-up to https://github.com/sneako/finch/pull/250.
Demo:
Mix.install([
  :req,
  {:finch, github: "wojtekmach/finch", branch: "wm-alpn-followup", override: true},
  :bandit
])

defmodule Main do
  def main do
    unless File.exists?("selfsigned.pem") do
      File.write!("selfsigned.pem", """
      -----BEGIN CERTIFICATE-----
      MIICzjCCAbYCCQDM0i9xf9D8qTANBgkqhkiG9w0BAQsFADApMQswCQYDVQQGEwJJ
      VDELMAkGA1UECAwCUk0xDTALBgNVBAcMBFJvbWUwHhcNMTcxMjI4MTAzMTE1WhcN
      MTgxMjI4MTAzMTE1WjApMQswCQYDVQQGEwJJVDELMAkGA1UECAwCUk0xDTALBgNV
      BAcMBFJvbWUwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQC6lBy3mpfB
      UrtclV/PFOM8OGiBNYVZmNJmZqCZCl2LQE5ekPrJ2Fh+zkcJcO19OxmseN+2F7VT
      zCYarty+h5ZXzNUmUcI2Ld60mfYwEfMjQRa4Tmp0K5PkphJ2gG9n9QOhFxky7KWz
      C84oe7Zm8iGni6wAQEEBOdo/qTCfGbPHzd39WUV+9Aft8HeDUcnpMhO6vXWDT3Yh
      658p04rXLzj8auyAZpfSq61x9ZS4WQYWB5vRLsJ4/V51RVGfA5nJYFKJ+cwZR4Hz
      bTRVc34rXaZS9ggIp8ktqL14NO6jfo9/dRng4RcTmkKMxU+0pWdTNZ7iPJX46/xM
      0XGxEd+7X4uHAgMBAAEwDQYJKoZIhvcNAQELBQADggEBABygqnZTQ4dsd5EFQKF7
      UT7ZfKi9a65e+iDGHikhUjHc+hSUMXFyP5RjpN6Z+4igi9LuWhJFZ0dqSZxDwCYG
      RdrMZSM/2yTBLKVdgcKXPuiV5eFPXHmYm39ru/WpNEqR/P28Q50xz/HJRoFhg3Qe
      AIlncG+v6AaUAKD8Qj6IZOLIVJuMaT8ONsDaa2LJiAz5uzKwgijEWiw7m83dvqGi
      FHkrj9/l5SQQVLGej/74Av+OFmMRI6nPc5lIu39atMRxsiPubrcQOVZmXZxRSEg8
      P7k3nBjtxCUhAnokjRqv/4rYfm8hvbqiRnL3rmtLlM1IF2L37nOqnfGo2NikjV+G
      1hU=
      -----END CERTIFICATE-----
      """)
    end

    unless File.exists?("selfsigned_key.pem") do
      File.write!("selfsigned_key.pem", """
      -----BEGIN PRIVATE KEY-----
      MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQC6lBy3mpfBUrtc
      lV/PFOM8OGiBNYVZmNJmZqCZCl2LQE5ekPrJ2Fh+zkcJcO19OxmseN+2F7VTzCYa
      rty+h5ZXzNUmUcI2Ld60mfYwEfMjQRa4Tmp0K5PkphJ2gG9n9QOhFxky7KWzC84o
      e7Zm8iGni6wAQEEBOdo/qTCfGbPHzd39WUV+9Aft8HeDUcnpMhO6vXWDT3Yh658p
      04rXLzj8auyAZpfSq61x9ZS4WQYWB5vRLsJ4/V51RVGfA5nJYFKJ+cwZR4HzbTRV
      c34rXaZS9ggIp8ktqL14NO6jfo9/dRng4RcTmkKMxU+0pWdTNZ7iPJX46/xM0XGx
      Ed+7X4uHAgMBAAECggEAW+VNi6UJ778m5z/vU5iPH38NAe7xgiLCJouPuDEhx89h
      ijRQQZBcbgB9fonvfwnX6FoUnaRpvB9F+Uh9Ex7HDvGlXl1Qkczf7wYR+rUskwWh
      AiAlUJiSHEErwNAbjxFfuz0cPTfPmTNMVCYyvduudc5WZj0/hzIOa+KSPxqysMq+
      kVEuoKm4yzVpbsvfVjGFhYyetFfqbURZ1d0EONGNiYCtwVPTP+gvcjeMTdgGMno4
      cpPHFF5RYsfnG/koaARHbOBtFrnkERpmABfsSL6DzwWtQys/ghxwaL2ZhjhdgbXO
      9vjstnXso9mjCAxVZaATyCs6QKXCn//T9BLRkutz+QKBgQDhlwuz2Df7TZwsCOqM
      PoYn0GhsY/hHupifEiWvDDtkGCAPuiw48HtCe1aCXFCtbSN/6E3Wdm7ZnG2q7RMY
      R5jxEEhnrBGEN7JQhAZPdktndVbupOXMgnGdiz/7nwHPCCghr3X/mdPWY0isMqx/
      T7Bl1bv2C5ipOAqHUER7AKd6awKBgQDTus7n3mwYQusGBqhygmpqOr/5JmTjOcFb
      fGbyuOE9JntLSGR6mJhlfOYQiESvFhBZEOtw4eDh/n7r8LnV48x6D009466hBY3+
      Fs5jTq+Ah2a9gxCRhSfUdEXhrJct+YHEjI+BNvXlUs/2D/y3rvc/2f+qa6nzegTI
      1NcmtlEyVQKBgE2dPjV+KqSXqyerWacuy9Fe7s58BqwHEwOHptd3CegCNOW0VAqz
      EnVpIfZv9IH2jsQvFLi4vqK4IzMvpeYwm/o0c/TXSp+G2h7BjbpBJOhPgr1Qlo+q
      QZTGmBjmOCUW1VfhmmN6dVvJhPNZ6+dRb4tZ4fVhQADYeybbAvSe4QBJAoGAbn1V
      6/pOPnrtWr+ut9MG5VizRbmbfFhvZuaMcq24HMkwHiExDikDnjKHfKkf7p58+X2y
      372ANW8xnL6Ku+uckTXbASkHwE+9wZL1MS2muFPwcYUr6ESsfFoQ/aurWPqTlZYk
      bTHZMEr+61F8d/5+WHvSx4RXtA9A3+zyOel6heECgYEAxqgiod1asd9g6Ao0vQ5Q
      YIQihF9Qq15stxj5H0qnBskvDKwS+He8GKjMUJjJss0gD43KCYhRvE8bmMD+rgVJ
      oy8Hp5oGeMVUHMG7ly8vdAj01RWxU2oIL5wlk3hX+4Pb6XyAN+NuCTMCQ8XukfTf
      AyfpMLycjN7uWN86CdTv/YY=
      -----END PRIVATE KEY-----
      """)
    end

    defmodule MyPlug do
      def init(options) do
        options
      end

      def call(conn, _) do
        {adapter, _} = conn.adapter
        Plug.Conn.send_resp(conn, 200, inspect(adapter))
      end
    end

    {:ok, _} =
      Bandit.start_link(
        scheme: :https,
        port: 4000,
        plug: MyPlug,
        certfile: Path.expand("selfsigned.pem"),
        keyfile: Path.expand("selfsigned_key.pem")
      )

    {:ok, _} =
      Finch.start_link(
        name: MyFinch,
        pools: %{
          default: [
            size: 1,
            protocols: [:http1, :http2],
            conn_opts: [
              transport_opts: [
                verify: :verify_none
              ]
            ]
          ]
        }
      )

    "Bandit.HTTP2.Adapter" = Req.get!("https://localhost:4000", finch: MyFinch).body
  end
end

Main.main()
sneako / finch

Deprecate :protocol in favour of :protocols #251
