ColumnWidth affectes table width

Proof for ColumnWidth issue: [document.pdf](https://github.com/simonbengtsson/jsPDF-AutoTable/files/672403/document.pdf

Issue 1: I am using columnWith for Employee Name.it takes table with out of box

Issue 2: With open saved pdf header border is not showing but view in new tab in browser it shows border right is availabe. Code here:

margin: {top: 70},
styles: {
    cellPadding: 3,
        fontSize: 8,
        valign: 'middle',

        overflow: 'linebreak',
        tableWidth: 'auto',
        //fileColor: [30, 30, 30],
        lineWidth: 1,
},
headerStyles: {
    //columnWidth: 'wrap',
    cellPadding: 2,
        lineWidth: 1,
        valign:'top',
        fontStyle: 'bold',
        halign: 'left',    //'center' or 'right'
        //fillColor: [250, 152, 95],
        //textColor: [78, 53, 73], //Black     
        textColor: [255, 255, 255], //White     
        fontSize: 8,

        rowHeight:20
},

[prabusendhil]

Thank you Simon.

[prabusendhil]

The above manner I added header and footer Simon