Don't use String#each_char in the tests
Don't use String#each_char in the tests

Ruby 1.8.6 doesn't have this method implemented and it is easy to work around.

Tested-by: Mark Somerville <f1b5a91d4d6ad523f2610114591c007e75d15084@scottishclimbs.com> [OS X 10.5, MRI 1.8.6]
Signed-off-by: Mark Somerville <f1b5a91d4d6ad523f2610114591c007e75d15084@scottishclimbs.com>

ConnorAtherton/rb-readline,mattn/rb-readline,rapid7/rb-readline,abinoam/rb-readline