all: update go.mod to go 1.17

For golang/go#49219

Change-Id: Ia0ede89fcf365c3feef9d34ac5a6b379749c015e
Reviewed-on: https://go-review.googlesource.com/c/debug/+/359595
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

go.mod

@@ -1,13 +1,16 @@
 module golang.org/x/debug
 
-go 1.11
+go 1.17
 
 require (
-	github.com/chzyer/logex v1.1.10 // indirect
 	github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e
+	github.com/spf13/cobra v0.0.3
+	golang.org/x/sys v0.0.0-20191113165036-4c7a9d0fe056
+)
+
+require (
+	github.com/chzyer/logex v1.1.10 // indirect
 	github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
-	github.com/spf13/cobra v0.0.3
 	github.com/spf13/pflag v1.0.3 // indirect
-	golang.org/x/sys v0.0.0-20191113165036-4c7a9d0fe056
 )