Add README for acceptance-tests

Makefile

@@ -1,4 +1,4 @@
-.PHONY: lint test static install uninstall cross
+.PHONY: lint test static install uninstall cross acceptance-tests
 GOPATH := $(shell go env GOPATH)
 VERSION := $(shell git describe --tags --dirty --always)
 BIN_DIR := $(GOPATH)/bin
@@ -14,6 +14,9 @@ lint: $(GOLINTER)
 test:
 	go test ./... -bench=. -benchmem
 
+acceptance-tests:
+	dagger call acceptance-tests --root-dir .:core-files
+
 # Compilation
 dev:
 	go build -ldflags "-X main.Version=dev-${VERSION}" ./cmd/tk

acceptance-tests/README.md

@@ -0,0 +1,11 @@
+# Acceptance tests
+
+These tests aim to cover some e2e use-cases like creating a new Tanka
+environment and pushing it up to an ephemeral Kubernetes cluster.
+
+To run these, you need to have the Dagger CLI >= 0.11 installed. Then you can
+execute the tests like this from the *root directory* of the project:
+
+```
+make acceptance-tests
+```