title: Not all ticks showing up in nvd3 line chart
body: <p>I am trying to create a line chart.</p>
  
  <p>Specifying ticks: 7 for a lineChart, but only 6 ticks are showing up.</p>
  
  <p>This is the data and option values</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>this.options = {
        chart: {
          type: 'lineChart',
          showYAxis:false,
          showLabels:true,
          showLegend:false,
          reduceXTicks: false,
          margin : {
            top: 20,
            right: 20,
            bottom: 40,
            left:20
          },
          x: function(d){ return d.x; },
          y: function(d){ return d.y; },
          xAxis: {
            tickFormat:function(d) { 
              return d3.time.format('%b %d')(new Date(d)); 
            },
            ticks:7
          }
        }
      };
  
      this.data=[
        {
          values: [    
          {x: new Date('2015-03-23'),y:10},
          {x:new Date('2015-03-24'),y:20},
          {x:new Date('2015-03-25'),y:5},
          {x: new Date('2015-03-26'),y:10},
          {x:new Date('2015-03-27'),y:15},
          {x:new Date('2015-03-28'),y:20},
          {x:new Date('2015-03-29'),y:40}
          ],
          key: 'Cosine Wave',
          color: '#d0021c',
          area:true
        }
      ]</code></pre>
  </div>
  </div>
  </p>
  
  <p>See the plunker -<a href="https://plnkr.co/edit/7zg62ezs730i40U0GTHy?p=preview" rel="nofollow noreferrer">https://plnkr.co/edit/7zg62ezs730i40U0GTHy?p=preview</a></p>
  
  <p>Any help would be appreciated.</p>