Add a Makefile

This is a very simple Makefile that just passes through to the current hack/*
scripts.  Only "make", "make test", and "make clean" are supported for now.

Makefile

@@ -0,0 +1,51 @@
+# Old-skool build tools.
+#
+# Targets (see each target for more information):
+#   all: Build code.
+#   check: Run tests.
+#   test: Run tests.
+#   clean: Clean up.
+
+OUT_DIR = _output
+
+export GOFLAGS
+
+# Build code.
+#
+# Args:
+#   WHAT: Directory names to build.  If any of these directories has a 'main'
+#     package, the build will produce executable files under $(OUT_DIR)/go/bin.
+#     If not specified, "everything" will be built.
+#   GOFLAGS: Extra flags to pass to 'go' when building.
+#
+# Example:
+#   make
+#   make all
+#   make all WHAT=cmd/kubelet GOFLAGS=-v
+all:
+	hack/build-go.sh $(WHAT)
+.PHONY: all
+
+# Build and run tests.
+#
+# Args:
+#   WHAT: Directory names to test.  All *_test.go files under these
+#     directories will be run.  If not specified, "everything" will be tested.
+#   TESTS: Same as WHAT.
+#   GOFLAGS: Extra flags to pass to 'go' when building.
+#
+# Example:
+#   make check
+#   make test
+#   make check WHAT=pkg/kubelet GOFLAGS=-v
+check test:
+	hack/test-go.sh $(WHAT) $(TESTS)
+.PHONY: check test
+
+# Remove all build artifacts.
+#
+# Example:
+#   make clean
+clean:
+	rm -rf $(OUT_DIR)
+.PHONY: clean