Fix http gremlin queries resulting in bad request (aws#37)

Changed http lambda code to submit axios POST gremlin query request with body as object instead of string to solve 400 bad request errors and then changed open cypher axios POST request as well for consistency.

templates/Lambda4AppSyncHTTP/index.mjs

@@ -61,10 +61,15 @@ export const handler = async (event) => {
             timeout: 20000
         };
 
-        if (resolver.language == 'opencypher') {
-            result = await axios.post(`https://${process.env.NEPTUNE_HOST}:${process.env.NEPTUNE_PORT}/opencypher`, `query=${encodeURIComponent(resolver.query)}&parameters=${encodeURIComponent(JSON.stringify(resolver.parameters))}`, myConfig);
+        if (resolver.language === 'opencypher') {
+            result = await axios.post(`https://${process.env.NEPTUNE_HOST}:${process.env.NEPTUNE_PORT}/opencypher`, {
+                query: resolver.query,
+                parameters: JSON.stringify(resolver.parameters)
+            }, myConfig);
         } else {
-            result = await axios.post(`https://${process.env.NEPTUNE_HOST}:${process.env.NEPTUNE_PORT}`, `gremlin=${encodeURIComponent(resolver.query)}`, myConfig);
+            result = await axios.post(`https://${process.env.NEPTUNE_HOST}:${process.env.NEPTUNE_PORT}/gremlin`, {
+                gremlin: resolver.query
+            }, myConfig);
         }
         if (LOGGING_ENABLED) console.log("Result: ", JSON.stringify(result.data, null, 2));
     } catch (err) {