Revert "Inculcating CRLs for revocation purposes."

[vkuznet]

Reverts #41 due to multiple errors at build time:

make
go clean; rm -rf pkg; CGO_ENABLED=0 go build -o auth-proxy-server -ldflags="-s -w -X main.gitVersion=`git rev-parse --short HEAD` -X main.tagVersion=`git describe --tags`"
# github.com/dmwm/auth-proxy-server
./crl.go:24:8: undefined: log.Warning
./crl.go:25:7: undefined: HardFail
./crl.go:30:8: undefined: log.Info
./crl.go:35:25: undefined: certIsRevokedOCSP
./crl.go:35:49: undefined: HardFail
./crl.go:36:7: undefined: log.Warning
./crl.go:37:6: undefined: HardFail
./crl.go:42:7: undefined: log.Info
./crl.go:51:15: undefined: HTTPClient
./crl.go:61:15: undefined: crlRead
./crl.go:61:15: too many errors
make: *** [build] Error 1