Remove ascent

[Zachari]

Problem：

It will cause unexpected translate while using ascent:

font-carrier/lib/class/glyph.js

Line 64 in 06e0c19

 path = svgpath(path).scale(1 / scale).translate(0, ascent).round(config.PATH_DECIMAL).toString() 

Resolve：

- path = svgpath(path).scale(1 / scale).translate(0, ascent).round(config.PATH_DECIMAL).toString()
+ path = svgpath(path).scale(1 / scale).translate(0, 0).round(config.PATH_DECIMAL).toString()

[一丝]

PR welcome!

[Zachari]

@yisibl see you latter