title: `missing tag key` when inserting to InfluxDB with inserting with multiple tags
body: <p>I created a new db <code>mydb</code> on Influxdb.
  Next I did <code>use mydb</code>
  When I run insert on my db, I run into error - 
  <code>ERR: {"error":"unable to parse 'angle, userid=1, product=pname value=5.1': missing tag key"}
  </code></p>
  
  <p>Here's the insert that I am running - 
  <code>INSERT angle, userid=1, product=dname value=5.1</code></p>