Once again, use native Ginkgo test runner instead of cmd/e2e.

This commit deletes cmd/e2e and updates hack/ginkgo-e2e.sh to use the
'ginkgo' command instead. All logic from cmd/e2e/e2e.go and
test/e2e/driver.go have been combined into the new file
test/e2e/e2e_test.go.

The test tarball now includes a built version of the test/e2e test
binary, which includes all tests under test/e2e. This was accomplished
by updating the build scripts to use 'go test -c' when a target name
ended with '.test', and adding a dependency on test/e2e/e2e.test.

This prebuilt test binary is passed to the Ginkgo runner in
hack/ginkgo-e2e.sh. In a future change, we can add support to run
Ginkgo against the source tree if it is available.

This change is generally intended to have no externally visible changes,
aside from the following caveats:
 - The -t/--tests flag has been removed
 - Calling cmd/e2e/e2e directly obviously won't work, but that was never
   intended to be supported anyway
 - If the GINKGO_PARALLEL environment variable is set to y, then ginkgo
   will run test specs in parallel. (Currently defaults to n, since some
   tests are broken in this mode.)

Additionally, several tests which made poor assumptions about cwd or
used testContext before it had been set have been fixed.

test/e2e/shell.go

@@ -19,7 +19,6 @@ package e2e
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os/exec"
 	"path/filepath"
 
@@ -27,36 +26,19 @@ import (
 )
 
 var _ = Describe("Shell", func() {
-	bashE2ERoot := filepath.Join(testContext.RepoRoot, "hack/e2e-suite")
+	defer GinkgoRecover()
 
-	// Slurp up all the tests in hack/e2e-suite
-	files, err := ioutil.ReadDir(bashE2ERoot)
-	if err != nil {
-		Fail(fmt.Sprintf("Error reading test suites from %v %v", bashE2ERoot, err.Error()))
-	}
-
-	for _, file := range files {
-		fileName := file.Name() // Make a copy
-		It(fmt.Sprintf("tests that %v passes", fileName), func() {
-			// A number of scripts only work on gce
-			if !providerIs("gce", "gke") {
-				By(fmt.Sprintf("Skipping Shell test %s, which is only supported for provider gce and gke (not %s)",
-					fileName, testContext.Provider))
-				return
-			}
-			runCmdTest(filepath.Join(bashE2ERoot, fileName))
-		})
-	}
+	It(fmt.Sprintf("tests that services.sh passes"), func() {
+		// The services script only works on gce/gke
+		if !providerIs("gce", "gke") {
+			By(fmt.Sprintf("Skipping Shell test services.sh, which is only supported for provider gce and gke (not %s)",
+				testContext.Provider))
+			return
+		}
+		runCmdTest(filepath.Join(testContext.RepoRoot, "hack/e2e-suite/services.sh"))
+	})
 })
 
-func absOrDie(path string) string {
-	out, err := filepath.Abs(path)
-	if err != nil {
-		panic(err)
-	}
-	return out
-}
-
 // Runs the given cmd test.
 func runCmdTest(path string) {
 	By(fmt.Sprintf("Running %v", path))