feat(refacto): move everything in internal package

This allows to install katenary with `go install` and to clean up the
project folder.

internal/generator/labels/labelstructs/envFrom_test.go

@@ -0,0 +1,17 @@
+package labelstructs
+
+import "testing"
+
+func TestEnvFromLabel(t *testing.T) {
+	ts := "- foo\n- bar"
+	tc, _ := EnvFromFrom(ts)
+	if len(tc) != 2 {
+		t.Errorf("Expected EnvFrom to have 2 items, got %d", len(tc))
+	}
+	if tc[0] != "foo" {
+		t.Errorf("Expected EnvFrom to contain 'foo', got %s", tc[0])
+	}
+	if tc[1] != "bar" {
+		t.Errorf("Expected EnvFrom to contain 'bar', got %s", tc[1])
+	}
+}