Uncompress doesn't enforce Buffer input

[simonecorsi]

If non-buffer input is provided to both uncompress functions the process crashes, this is uncatchable!

Looking in lib.rs uncompress#L143 declaration it expects a <JsBuffer>.

I've pushed a fix in #39

Error dump

/Users/scdev/.volta/tools/image/node/14.15.1/bin/node[45976]: ../src/node_buffer.cc:243:char *node::Buffer::Data(Local<v8::Value>): Assertion `val->IsArrayBufferView()' failed.
 1: 0x1012e2bc5 node::Abort() (.cold.1) [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]
 2: 0x1000a5cb9 node::Abort() [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]
 3: 0x1000a5b21 node::Assert(node::AssertionInfo const&) [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]
 4: 0x100080ee9 node::Buffer::Data(v8::Local<v8::Value>) [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]
 5: 0x10007c4e3 napi_get_buffer_info [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]
 6: 0x105471af2 napi_register_module_v1 [/Users/scdev/develop/projects/@immo/website-next/node_modules/@napi-rs/snappy-darwin-x64/snappy.darwin-x64.node]
 7: 0x105470641 napi_register_module_v1 [/Users/scdev/develop/projects/@immo/website-next/node_modules/@napi-rs/snappy-darwin-x64/snappy.darwin-x64.node]
 8: 0x10546a064 napi_register_module_v1 [/Users/scdev/develop/projects/@immo/website-next/node_modules/@napi-rs/snappy-darwin-x64/snappy.darwin-x64.node]
 9: 0x10006360a v8impl::(anonymous namespace)::FunctionCallbackWrapper::Invoke(v8::FunctionCallbackInfo<v8::Value> const&) [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]
10: 0x100259878 v8::internal::FunctionCallbackArguments::Call(v8::internal::CallHandlerInfo) [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]
11: 0x100258e0c v8::internal::MaybeHandle<v8::internal::Object> v8::internal::(anonymous namespace)::HandleApiCallHelper<false>(v8::internal::Isolate*, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::FunctionTemplateInfo>, v8::internal::Handle<v8::internal::Object>, v8::internal::BuiltinArguments) [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]
12: 0x100258532 v8::internal::Builtin_Impl_HandleApiCall(v8::internal::BuiltinArguments, v8::internal::Isolate*) [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]
13: 0x100a796d9 Builtins_CEntry_Return1_DontSaveFPRegs_ArgvOnStack_BuiltinExit [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]
14: 0x100a129a2 Builtins_InterpreterEntryTrampoline [/Users/scdev/.volta/tools/image/node/14.15.1/bin/node]