skulpin: Support for wayland is not implemented

Originally reported as https://github.com/Kethku/neovide/issues/33,

thread 'main' panicked at 'internal error: entered unreachable code', /home/sawyer/.cargo/registry/src/github.com-1ecc6299db9ec823/skulpin-0.5.0/src/renderer/window_support.rs:45:14
stack backtrace:
   0:     0x555ec12408f4 - backtrace::backtrace::libunwind::trace::h65597d255cb1398b
                               at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/libunwind.rs:88
   1:     0x555ec12408f4 - backtrace::backtrace::trace_unsynchronized::hd4f479d7150ec4a0
                               at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/mod.rs:66
   2:     0x555ec12408f4 - std::sys_common::backtrace::_print_fmt::h015072984a2b172c
                               at src/libstd/sys_common/backtrace.rs:77
   3:     0x555ec12408f4 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h6df05d3335f32194
                               at src/libstd/sys_common/backtrace.rs:61
   4:     0x555ec1266d6c - core::fmt::write::h1f444f4312eb6c27
                               at src/libcore/fmt/mod.rs:1028
   5:     0x555ec123da37 - std::io::Write::write_fmt::h8d147888220078ef
                               at src/libstd/io/mod.rs:1412
   6:     0x555ec1242e4e - std::sys_common::backtrace::_print::h8a6df0fa81d6af62
                               at src/libstd/sys_common/backtrace.rs:65
   7:     0x555ec1242e4e - std::sys_common::backtrace::print::h6f05b4733407e509
                               at src/libstd/sys_common/backtrace.rs:50
   8:     0x555ec1242e4e - std::panicking::default_hook::{{closure}}::h0d0a23bd02315dd8
                               at src/libstd/panicking.rs:188
   9:     0x555ec1242b41 - std::panicking::default_hook::h8d15a9aecb4efac6
                               at src/libstd/panicking.rs:205
  10:     0x555ec124354b - std::panicking::rust_panic_with_hook::hbe174577402a475d
                               at src/libstd/panicking.rs:464
  11:     0x555ec11c0783 - std::panicking::begin_panic::hfc51a6f59961fcca
                               at /rustc/73528e339aae0f17a15ffa49a8ac608f50c6cf14/src/libstd/panicking.rs:400
  12:     0x555ec09e7efa - skulpin::renderer::window_support::create_surface::hdafadb24e11b4148
                               at /home/sawyer/.cargo/registry/src/github.com-1ecc6299db9ec823/skulpin-0.5.0/src/renderer/window_support.rs:45
  13:     0x555ec09c2055 - skulpin::renderer::device::VkDevice::new::hb87b290a8f6fd6cc
                               at /home/sawyer/.cargo/registry/src/github.com-1ecc6299db9ec823/skulpin-0.5.0/src/renderer/device.rs:50
  14:     0x555ec09b91c1 - skulpin::renderer::renderer::Renderer::new::hc5d4e7bf2204550e
                               at /home/sawyer/.cargo/registry/src/github.com-1ecc6299db9ec823/skulpin-0.5.0/src/renderer/renderer.rs:249
  15:     0x555ec09b8d7a - skulpin::renderer::renderer::RendererBuilder::build::h4991be65e14a1fbf
                               at /home/sawyer/.cargo/registry/src/github.com-1ecc6299db9ec823/skulpin-0.5.0/src/renderer/renderer.rs:163
  16:     0x555ec07eda5b - neovide::window::ui_loop::hdcad53034d51e52c
                               at src/window.rs:42
  17:     0x555ec08519f9 - neovide::main::hcc0d95a0303618df
                               at src/main.rs:91
  18:     0x555ec084e520 - std::rt::lang_start::{{closure}}::hfbadcd0574f266cc
                               at /rustc/73528e339aae0f17a15ffa49a8ac608f50c6cf14/src/libstd/rt.rs:61
  19:     0x555ec1242f73 - std::rt::lang_start_internal::{{closure}}::h6ea535ec5c50fc3e
                               at src/libstd/rt.rs:48
  20:     0x555ec1242f73 - std::panicking::try::do_call::h631c6408dfccc6f5
                               at src/libstd/panicking.rs:287
  21:     0x555ec124b2ca - __rust_maybe_catch_panic
                               at src/libpanic_unwind/lib.rs:78
  22:     0x555ec1243a2d - std::panicking::try::hab539b2d1255d635
                               at src/libstd/panicking.rs:265
  23:     0x555ec1243a2d - std::panic::catch_unwind::hd5e0a26424bd7f34
                               at src/libstd/panic.rs:396
  24:     0x555ec1243a2d - std::rt::lang_start_internal::h3bdc4c7d98181bf9
                               at src/libstd/rt.rs:47
  25:     0x555ec084e4f9 - std::rt::lang_start::h1cd89b6af8d283da
                               at /rustc/73528e339aae0f17a15ffa49a8ac608f50c6cf14/src/libstd/rt.rs:61
  26:     0x555ec0851a7a - main
  27:     0x7fb37ef6c153 - __libc_start_main
  28:     0x555ec0794e9e - _start
  29:                0x0 - <unknown>

Panic comes from https://github.com/aclysma/skulpin/blob/master/src/renderer/window_support.rs#L45