add support arrays on mapping

[vkd]

var s struct {
	Nums [2]int `form:"nums"`
}
req := formPostRequest("", "nums=3&nums=8")
Form.Bind(req, &s)

[codecov]

Codecov Report

Merging #1797 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1797      +/-   ##
==========================================
+ Coverage   98.62%   98.63%   +<.01%     
==========================================
  Files          41       41              
  Lines        2113     2124      +11     
==========================================
+ Hits         2084     2095      +11     
  Misses         18       18              
  Partials       11       11

Impacted Files	Coverage Δ
binding/form_mapping.go	100% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update cab0749...35314e5. Read the comment docs.