config tests added,

titles tests added,
.env file support added with dotenv,
README.md file updated for .evn file support,
database lost connection bug crash fixed,
session server run_session long timeout bug fixed,
links module added,
webrtc_proc json arguments added,
app_proc stdout and stderr support added,
infinity app_proc spawn freeze bug fixed

README.md

@@ -1,3 +1,14 @@
 # pixel-streaming-session-server
 
-pixel streaming session server
+pixel streaming session server
+
+configure environment variables with .env file
+
+.env:
+
+PORT=
+EXTERNAL_DOMAIN=""
+COORDINATOR_URL=""
+DATABASE_URL=""
+DATABASE_NAME=""
+WEBRTC_PORT_BEGIN=