build: use module to get server version in travis

Author: dougwilson

.travis.yml

@@ -75,7 +75,7 @@ install:
 
 before_script:
   - "docker --version"
-  - "docker exec mysql mysql -e 'select version()'"
+  - "node tool/mysql-version.js"
 
 script:
   # Run test script

tool/mysql-version.js

@@ -0,0 +1,19 @@
+var common = require('../test/common');
+
+process.nextTick(run);
+
+function run() {
+  var conn = common.createConnection();
+
+  conn.connect(function () {
+    conn.destroy();
+
+    try {
+      console.log(conn._protocol._handshakeInitializationPacket.serverVersion);
+      process.exit(0);
+    } catch (e) {
+      console.error('unable to get mysql version');
+      process.exit(1);
+    }
+  });
+}