feat: update stdlib mapping for go1.16

- drop stdlib for go1.14
- generate stdlib for go1.16
-  update CI configuration.

stdlib/go1_16_encoding_hex.go

@@ -0,0 +1,30 @@
+// Code generated by 'yaegi extract encoding/hex'. DO NOT EDIT.
+
+// +build go1.16
+
+package stdlib
+
+import (
+	"encoding/hex"
+	"reflect"
+)
+
+func init() {
+	Symbols["encoding/hex"] = map[string]reflect.Value{
+		// function, constant and variable definitions
+		"Decode":         reflect.ValueOf(hex.Decode),
+		"DecodeString":   reflect.ValueOf(hex.DecodeString),
+		"DecodedLen":     reflect.ValueOf(hex.DecodedLen),
+		"Dump":           reflect.ValueOf(hex.Dump),
+		"Dumper":         reflect.ValueOf(hex.Dumper),
+		"Encode":         reflect.ValueOf(hex.Encode),
+		"EncodeToString": reflect.ValueOf(hex.EncodeToString),
+		"EncodedLen":     reflect.ValueOf(hex.EncodedLen),
+		"ErrLength":      reflect.ValueOf(&hex.ErrLength).Elem(),
+		"NewDecoder":     reflect.ValueOf(hex.NewDecoder),
+		"NewEncoder":     reflect.ValueOf(hex.NewEncoder),
+
+		// type definitions
+		"InvalidByteError": reflect.ValueOf((*hex.InvalidByteError)(nil)),
+	}
+}