(maint) Pin rake version to 10.1.0 for 1.8 compat
Merge branch 'maint/3.2.x-ruby-rake-1.8-compat' into 3.2.x
Merge branch '3.2.x' into 3.x
Merge branch '3.x' into 4.x
Merge branch '4.x'
Update README.markdown

Add code block for validate_slength.
Merge pull request #236 from PierreRambaud/patch-1

Update README.markdown