update Go to 1.16, drop support for 1.14

stream_test.go

@@ -1,6 +1,7 @@
 package quic
 
 import (
+	"errors"
 	"io"
 	"os"
 	"strconv"
@@ -94,3 +95,13 @@ var _ = Describe("Stream", func() {
 		})
 	})
 })
+
+var _ = Describe("Deadline Error", func() {
+	It("is a net.Error that wraps os.ErrDeadlineError", func() {
+		err := deadlineError{}
+		Expect(err.Temporary()).To(BeTrue())
+		Expect(err.Timeout()).To(BeTrue())
+		Expect(errors.Is(err, os.ErrDeadlineExceeded)).To(BeTrue())
+		Expect(errors.Unwrap(err)).To(Equal(os.ErrDeadlineExceeded))
+	})
+})