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/containers/storage/pkg/ioutils/writeflusher.go

@@ -0,0 +1,92 @@
+package ioutils
+
+import (
+	"io"
+	"sync"
+)
+
+// WriteFlusher wraps the Write and Flush operation ensuring that every write
+// is a flush. In addition, the Close method can be called to intercept
+// Read/Write calls if the targets lifecycle has already ended.
+type WriteFlusher struct {
+	w           io.Writer
+	flusher     flusher
+	flushed     chan struct{}
+	flushedOnce sync.Once
+	closed      chan struct{}
+	closeLock   sync.Mutex
+}
+
+type flusher interface {
+	Flush()
+}
+
+var errWriteFlusherClosed = io.EOF
+
+func (wf *WriteFlusher) Write(b []byte) (n int, err error) {
+	select {
+	case <-wf.closed:
+		return 0, errWriteFlusherClosed
+	default:
+	}
+
+	n, err = wf.w.Write(b)
+	wf.Flush() // every write is a flush.
+	return n, err
+}
+
+// Flush the stream immediately.
+func (wf *WriteFlusher) Flush() {
+	select {
+	case <-wf.closed:
+		return
+	default:
+	}
+
+	wf.flushedOnce.Do(func() {
+		close(wf.flushed)
+	})
+	wf.flusher.Flush()
+}
+
+// Flushed returns the state of flushed.
+// If it's flushed, return true, or else it return false.
+func (wf *WriteFlusher) Flushed() bool {
+	// BUG(stevvooe): Remove this method. Its use is inherently racy. Seems to
+	// be used to detect whether or a response code has been issued or not.
+	// Another hook should be used instead.
+	var flushed bool
+	select {
+	case <-wf.flushed:
+		flushed = true
+	default:
+	}
+	return flushed
+}
+
+// Close closes the write flusher, disallowing any further writes to the
+// target. After the flusher is closed, all calls to write or flush will
+// result in an error.
+func (wf *WriteFlusher) Close() error {
+	wf.closeLock.Lock()
+	defer wf.closeLock.Unlock()
+
+	select {
+	case <-wf.closed:
+		return errWriteFlusherClosed
+	default:
+		close(wf.closed)
+	}
+	return nil
+}
+
+// NewWriteFlusher returns a new WriteFlusher.
+func NewWriteFlusher(w io.Writer) *WriteFlusher {
+	var fl flusher
+	if f, ok := w.(flusher); ok {
+		fl = f
+	} else {
+		fl = &NopFlusher{}
+	}
+	return &WriteFlusher{w: w, flusher: fl, closed: make(chan struct{}), flushed: make(chan struct{})}
+}