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/reexec/reexec.go

@@ -0,0 +1,47 @@
+package reexec
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+var registeredInitializers = make(map[string]func())
+
+// Register adds an initialization func under the specified name
+func Register(name string, initializer func()) {
+	if _, exists := registeredInitializers[name]; exists {
+		panic(fmt.Sprintf("reexec func already registered under name %q", name))
+	}
+
+	registeredInitializers[name] = initializer
+}
+
+// Init is called as the first part of the exec process and returns true if an
+// initialization function was called.
+func Init() bool {
+	initializer, exists := registeredInitializers[os.Args[0]]
+	if exists {
+		initializer()
+
+		return true
+	}
+	return false
+}
+
+func naiveSelf() string {
+	name := os.Args[0]
+	if filepath.Base(name) == name {
+		if lp, err := exec.LookPath(name); err == nil {
+			return lp
+		}
+	}
+	// handle conversion of relative paths to absolute
+	if absName, err := filepath.Abs(name); err == nil {
+		return absName
+	}
+	// if we couldn't get absolute name, return original
+	// (NOTE: Go only errors on Abs() if os.Getwd fails)
+	return name
+}