Use snake_case for claim predicate JSON fields. (#3086)

Author: abuiles

Diff for: services/horizon/internal/resourceadapter/operations_test.go

@@ -143,8 +143,8 @@ func TestPopulateOperation_CreateClaimableBalance(t *testing.T) {
 					"and": [
 						{
 							"or": [
-								{"relBefore":"12"},
-								{"absBefore": "2020-08-26T11:15:39Z"}
+								{"rel_before":"12"},
+								{"abs_before": "2020-08-26T11:15:39Z"}
 							]
 						},
 						{

Diff for: xdr/json.go

@@ -11,8 +11,8 @@ type claimPredicateJSON struct {
 	Or            *[]claimPredicateJSON `json:"or,omitempty"`
 	Not           *claimPredicateJSON   `json:"not,omitempty"`
 	Unconditional bool                  `json:"unconditional,omitempty"`
-	AbsBefore     *time.Time            `json:"absBefore,omitempty"`
-	RelBefore     *int64                `json:"relBefore,string,omitempty"`
+	AbsBefore     *time.Time            `json:"abs_before,omitempty"`
+	RelBefore     *int64                `json:"rel_before,string,omitempty"`
 }
 
 func convertPredicatesToXDR(input []claimPredicateJSON) ([]ClaimPredicate, error) {

Diff for: xdr/json_test.go

@@ -41,7 +41,7 @@ func TestClaimPredicateJSON(t *testing.T) {
 	assert.NoError(t, err)
 	assert.JSONEq(
 		t,
-		`{"and":[{"or":[{"relBefore":"12"},{"absBefore":"2020-08-26T11:15:39Z"}]},{"not":{"unconditional":true}}]}`,
+		`{"and":[{"or":[{"rel_before":"12"},{"abs_before":"2020-08-26T11:15:39Z"}]},{"not":{"unconditional":true}}]}`,
 		string(serialized),
 	)