tools: update arguments

Modify the tools to take the certificate and private key directly as arguments, rather than the path to the directory that contains them.

Change-Id: I18010c27379d8e985b596bed0159155343265112
diff --git a/tools/dvpn/dvpn.h b/tools/dvpn/dvpn.h
index 6331907..e17775a 100644
--- a/tools/dvpn/dvpn.h
+++ b/tools/dvpn/dvpn.h
@@ -48,8 +48,7 @@
 class Dvpn
 {
 public:
-    Dvpn(const std::filesystem::path& path,
-         dht::crypto::Identity identity,
+    Dvpn(dht::crypto::Identity identity,
          const std::string& bootstrap,
          const std::string& turn_host,
          const std::string& turn_user,
@@ -73,8 +72,7 @@
 {
 public:
     // Build a server
-    DvpnServer(const std::filesystem::path& path,
-               dht::crypto::Identity identity,
+    DvpnServer(dht::crypto::Identity identity,
                const std::string& bootstrap,
                const std::string& turn_host,
                const std::string& turn_user,
@@ -89,7 +87,6 @@
 public:
     // Build a client
     DvpnClient(dht::InfoHash peer_id,
-               const std::filesystem::path& path,
                dht::crypto::Identity identity,
                const std::string& bootstrap,
                const std::string& turn_host,