fix(sdam): we can't use Array.includes yet

Author: mbroadst

lib/sdam/server_description.js

@@ -66,7 +66,9 @@ class ServerDescription {
    * @return {Boolean} Is this server available for writes
    */
   get isWritable() {
-    return [ServerType.RSPrimary, ServerType.Standalone, ServerType.Mongos].includes(this.type);
+    return (
+      [ServerType.RSPrimary, ServerType.Standalone, ServerType.Mongos].indexOf(this.type) !== -1
+    );
   }
 }
 

lib/uri_parser.js

@@ -109,7 +109,7 @@ function parseSrvConnectionString(uri, options, callback) {
 
         record = record[0];
         record = record.length > 1 ? record.join('') : record[0];
-        if (!record.includes('authSource') && !record.includes('replicaSet')) {
+        if (record.indexOf('authSource') === -1 && record.indexOf('replicaSet') === -1) {
           return callback(
             new MongoParseError('Text record must only set `authSource` or `replicaSet`')
           );