Add test for OPEN_FULLMUTEX (TryGhost#1)

Author: davedoesdev

test/constants.test.js

@@ -6,6 +6,7 @@ describe('constants', function() {
         assert.ok(sqlite3.OPEN_READONLY === 1);
         assert.ok(sqlite3.OPEN_READWRITE === 2);
         assert.ok(sqlite3.OPEN_CREATE === 4);
+        assert.ok(sqlite3.OPEN_FULLMUTEX === 0x00010000);
     });
 
     it('should have the right error flags', function() {