backported strict_encode64 method for ruby 1.8.7
backported strict_encode64 method for ruby 1.8.7

Gataniel/signet,rusikf/signet,rhenry1989/signet,rhenry1989/signet,rusikf/signet,jonahglover/signet,jonahglover/signet,googleapis/signet,Gataniel/signet,googleapis/signet,rhenry1989/signet,jonahglover/signet,googleapis/signet,rusikf/signet,Gataniel/signet