Update go version in go.mod (go1.16).

_examples/go.mod

@@ -1,6 +1,6 @@
 module github.com/cucumber/godog/_examples
 
-go 1.17
+go 1.16
 
 replace github.com/cucumber/godog => ../
 
@@ -13,15 +13,6 @@ require (
 )
 
 require (
-	github.com/cucumber/gherkin-go/v19 v19.0.3 // indirect
-	github.com/cucumber/messages-go/v16 v16.0.1 // indirect
-	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/gofrs/uuid v4.2.0+incompatible // indirect
-	github.com/hashicorp/go-immutable-radix v1.3.1 // indirect
-	github.com/hashicorp/go-memdb v1.3.2 // indirect
-	github.com/hashicorp/golang-lru v0.5.4 // indirect
 	github.com/kr/pretty v0.3.0 // indirect
 	github.com/lib/pq v1.10.3 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
-	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )

go.mod

@@ -1,6 +1,6 @@
 module github.com/cucumber/godog
 
-go 1.17
+go 1.16
 
 require (
 	github.com/cucumber/gherkin-go/v19 v19.0.3
@@ -15,14 +15,8 @@ require (
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/gofrs/uuid v4.2.0+incompatible // indirect
-	github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1 // indirect
 	github.com/hashicorp/go-immutable-radix v1.3.1 // indirect
 	github.com/hashicorp/go-uuid v1.0.2 // indirect
-	github.com/hashicorp/golang-lru v0.5.4 // indirect
-	github.com/inconshreveable/mousetrap v1.0.0 // indirect
-	github.com/jtolds/gls v4.20.0+incompatible // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )