badges with higher resolution

[liuggio]

to display badges with a higher resolution with the markdown syntax is not possible since it does not allow the width,
but github also allows you to insert html on markdown, so it would be helpful to print badges with higher resolution:

with:

<img src="http://.../ExcelBundle/v/stable.png?size=double" width='100px'>

note:

#97 doesn't allow to create fixed images