Add support for contains operator (#63)

* add support for contains op

* bump version v.12.0

Author: wagslane

Diff for: client/lessons.go

@@ -24,6 +24,7 @@ type OperatorType string
 const (
 	OpEquals      OperatorType = "eq"
 	OpGreaterThan OperatorType = "gt"
+	OpContains    OperatorType = "contains"
 )
 
 type HTTPTestJSONValue struct {

Diff for: render/http.go

@@ -272,6 +272,8 @@ func prettyPrintHTTPTest(test api.HTTPTest, variables map[string]string) string
 			op = "to be equal to"
 		} else if test.JSONValue.Operator == api.OpGreaterThan {
 			op = "to be greater than"
+		} else if test.JSONValue.Operator == api.OpContains {
+			op = "contains"
 		}
 		expecting := fmt.Sprintf("Expecting JSON at %v %s %v", test.JSONValue.Path, op, val)
 		return checks.InterpolateVariables(expecting, variables)

Diff for: version.txt

@@ -1 +1 @@
-v1.11.1
+v1.12.0