Add UPSERT for POST with Prefer:resoultion=merge/ignore-duplicates

test/fixtures/data.sql

@@ -334,6 +334,12 @@ INSERT INTO part VALUES (1), (2), (3), (4);
 
 TRUNCATE TABLE being_part CASCADE;
 INSERT INTO being_part VALUES (1,1), (2,1), (3,2), (4,3);
---
--- PostgreSQL database dump complete
---
+
+TRUNCATE TABLE employees CASCADE;
+INSERT INTO employees VALUES
+  ('Frances M.', 'Roe', '24000', 'One-Up Realty', 'Author'),
+  ('Daniel B.', 'Lyon', '36000', 'Dubrow''s Cafeteria', 'Packer'),
+  ('Edwin S.', 'Smith', '48000', 'Pro Garden Management', 'Marine biologist');
+
+TRUNCATE TABLE tiobe_pls CASCADE;
+INSERT INTO tiobe_pls VALUES ('Java', 1), ('C', 2), ('Python', 4);

test/fixtures/privileges.sql

@@ -63,6 +63,8 @@ GRANT ALL ON TABLE
     , part
     , leak
     , perf_articles
+    , employees
+    , tiobe_pls
 TO postgrest_test_anonymous;
 
 GRANT INSERT ON TABLE insertonly TO postgrest_test_anonymous;

test/fixtures/schema.sql

@@ -1357,3 +1357,17 @@ create table test.perf_articles(
   id integer not null,
   body text not null
 );
+
+create table test.employees(
+  first_name text,
+  last_name text,
+  salary money,
+  company text,
+  occupation text,
+  primary key(first_name, last_name)
+);
+
+create table test.tiobe_pls(
+  name text primary key,
+  rank smallint
+);