Add NakedretBear

[Makman2]

Implement a new linter bear that wraps https://github.com/alexkohler/nakedret
nakedret checks for functions whether they use so called "naked returns" in go, when they exceed a specified length. If a function is very long, naked returns hinder readability and maintenance. They should be avoided in such cases.

[SubbulakshmiRS]

this bear should check for naked returns in functions of lengths more than the specified number right ?
If present , a warning should be given out ?
Also the checking is done by nakedret -l no_of_lines filename
@Makman2 is this correct ?

[jayvdb]

Is this linter wrapped by gometalinter?

[naveentvelu]

@jayvdb I guess this is repo for gometalinter https://github.com/alecthomas/gometalinter.
It supports nakedret linter.