tests/image: move constants to a subpackage

The cmd/osbuild-image-tests package is becoming bigger than I would like to.
It will be nice to split it to some smaller pieces at some point.
This commit does the first step - splits off the first subpackage containing
all the constants.

cmd/osbuild-image-tests/constants/constants-travis.go

@@ -0,0 +1,32 @@
+// +build travis
+
+package constants
+
+import "os/exec"
+
+func GetOsbuildCommand(store string) *exec.Cmd {
+	cmd := exec.Command(
+		"python3",
+		"-m", "osbuild",
+		"--libdir", ".",
+		"--store", store,
+		"--json",
+		"-",
+	)
+	cmd.Dir = "osbuild"
+	return cmd
+}
+
+var TestPaths = struct {
+	ImageInfo          string
+	PrivateKey         string
+	TestCasesDirectory string
+	UserData           string
+	MetaData           string
+}{
+	ImageInfo:          "tools/image-info",
+	PrivateKey:         "test/keyring/id_rsa",
+	TestCasesDirectory: "test/cases",
+	UserData:           "test/cloud-init/user-data",
+	MetaData:           "test/cloud-init/meta-data",
+}

cmd/osbuild-image-tests/constants/constants.go

@@ -0,0 +1,28 @@
+// +build integration,!travis
+
+package constants
+
+import "os/exec"
+
+func GetOsbuildCommand(store string) *exec.Cmd {
+	return exec.Command(
+		"osbuild",
+		"--store", store,
+		"--json",
+		"-",
+	)
+}
+
+var TestPaths = struct {
+	ImageInfo          string
+	PrivateKey         string
+	TestCasesDirectory string
+	UserData           string
+	MetaData           string
+}{
+	ImageInfo:          "/usr/libexec/osbuild-composer/image-info",
+	PrivateKey:         "/usr/share/tests/osbuild-composer/keyring/id_rsa",
+	TestCasesDirectory: "/usr/share/tests/osbuild-composer/cases",
+	UserData:           "/usr/share/tests/osbuild-composer/cloud-init/user-data",
+	MetaData:           "/usr/share/tests/osbuild-composer/cloud-init/meta-data",
+}