encoding/openapi: date-time & string format

There is no ```string``` format and the date-format in OpenAPI is ```date-time```.
https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md#data-types

Closes #426
cuelang/cue#426

GitOrigin-RevId: f8270d4c331537d23eb41a936d663dff84ad4d18
Change-Id: I5b09ace4d4ca9170df368710fea135da68f38b37
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/6420
Reviewed-by: Marcel van Lohuizen <[email protected]>

Author: wroge

encoding/openapi/types.go

@@ -27,23 +27,22 @@ import (
 	"cuelang.org/go/cue/token"
 )
 
-// See https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md#format
+// See https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md#data-types
 var cueToOpenAPI = map[string]string{
 	"int32": "int32",
 	"int64": "int64",
 
 	"float64": "double",
 	"float32": "float",
 
-	"string": "string",
-	"bytes":  "binary",
+	"bytes": "binary",
 
-	"time.Time":                  "dateTime",
+	"time.Time":                  "date-time",
 	`time.Format ("2006-01-02")`: "date",
 
 	// TODO: if a format is more strict (e.g. using zeros instead of nines
 	// for fractional seconds), we could still use this as an approximation.
-	`time.Format ("2006-01-02T15:04:05.999999999Z07:00")`: "dateTime",
+	`time.Format ("2006-01-02T15:04:05.999999999Z07:00")`: "date-time",
 
 	// TODO:  password.
 }