adds a suite struct that uses Require() as default

[rolancia]

Summary

a suite uses Require() as default is needed. i guess implement a new suite is simple way in its design.

Changes

SuiteRequire is added.

Motivation

some cases would need the suite uses Require as default.

data := getDate()
s.NotNil(data)
s.Equal(10, data.value) // would raise panic, not Fail

so we should be care to use s.Require().NotNil(data) not good to read.

Related issues

#829