Build and install from GOPATH

* Rename 'vendor/src' -> 'vendor'
  * Ignore vendor/ instead of vendor/src/ for lint
* Rename 'cmd/client' -> 'cmd/ocic' to make it 'go install'able
* Rename 'cmd/server' -> 'cmd/ocid' to make it 'go install'able
* Update Makefile to build and install from GOPATH
* Update tests to locate ocid/ocic in GOPATH/bin
* Search for binaries in GOPATH/bin instead of PATH
* Install tools using `go get -u`, so they are updated on each run

Signed-off-by: Jonathan Yu <jawnsy@redhat.com>

vendor/github.com/coreos/go-systemd/daemon/sdnotify.go

@@ -0,0 +1,38 @@
+// Code forked from Docker project
+package daemon
+
+import (
+	"net"
+	"os"
+)
+
+// SdNotify sends a message to the init daemon. It is common to ignore the error.
+// It returns one of the following:
+// (false, nil) - notification not supported (i.e. NOTIFY_SOCKET is unset)
+// (false, err) - notification supported, but failure happened (e.g. error connecting to NOTIFY_SOCKET or while sending data)
+// (true, nil) - notification supported, data has been sent
+func SdNotify(state string) (sent bool, err error) {
+	socketAddr := &net.UnixAddr{
+		Name: os.Getenv("NOTIFY_SOCKET"),
+		Net:  "unixgram",
+	}
+
+	// NOTIFY_SOCKET not set
+	if socketAddr.Name == "" {
+		return false, nil
+	}
+
+	conn, err := net.DialUnix(socketAddr.Net, nil, socketAddr)
+	// Error connecting to NOTIFY_SOCKET
+	if err != nil {
+		return false, err
+	}
+	defer conn.Close()
+
+	_, err = conn.Write([]byte(state))
+	// Error sending the message
+	if err != nil {
+		return false, err
+	}
+	return true, nil
+}