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/system/filesys.go

@@ -0,0 +1,19 @@
+// +build !windows
+
+package system
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// MkdirAll creates a directory named path along with any necessary parents,
+// with permission specified by attribute perm for all dir created.
+func MkdirAll(path string, perm os.FileMode) error {
+	return os.MkdirAll(path, perm)
+}
+
+// IsAbs is a platform-specific wrapper for filepath.IsAbs.
+func IsAbs(path string) bool {
+	return filepath.IsAbs(path)
+}