update readme, remove tcp/icmp

tcp.go

@@ -1,15 +0,0 @@
-package cachet
-
-type TCPMonitor struct {
-	AbstractMonitor `mapstructure:",squash"`
-
-	// same as output from net.JoinHostPort
-	// defaults to parsed config from /etc/resolv.conf when empty
-	DNSServer string
-
-	// Will be converted to FQDN
-	Domain string
-	Type   string
-	// expected answers (regex)
-	Expect []string
-}