Self contained signal cmd build (#82)

* Moved Signal CMD to Signal directory

* Removed config dir and fixed a parameter typo

* removed attempt to create ssl directory

* Update Signal build configuration

* move Signal documentation to its directory

* removed unused variables

* test build management and signal

* User run as subcommand to execute the signal daemon

signal/main.go

@@ -0,0 +1,12 @@
+package main
+
+import (
+	"github.com/wiretrustee/wiretrustee/signal/cmd"
+	"os"
+)
+
+func main() {
+	if err := cmd.Execute(); err != nil {
+		os.Exit(1)
+	}
+}