Replace b.Loop() with correct benchmark loop syntax in Go

[snk-git-hub]

Replace b.Loop() with for i:= 0; i< b.N; i++ syntax in

• blogrenderer/renderer_test.go
• concurrency/v1/check_websites_benchmark_test.go
• concurrency/v2/check_websites_benchmark_test.go
• concurrency/v3/check_websites_benchmark_test.go
• for/vx/repeat_test.go
• concurrency.md
• html-templates.md (2 instances)
• iteration.md (2 instances)

Verified with ./build.sh - all tests pass

Fixes #869

[quii]

Love it, thanks

[nicholasbraun]

Why is i := 0; i < b.N: i++ the correct syntax? The go blog says the b.Loop() syntax is the preferred way to do it.

[quii]

Oh yeah, i totally misread the PR in my lack of coffee haze. Think i'll revert!

[quii]

I legit read it as going from the old syntax to the new one :D