Implemented handshake and heartbeat

Implemented handshake in json server and handoff to endpoint

Endpoint handles connector handshake accept/decline then launches both
its IO threads alongside its heartbeat thread which contains simple
timeout logic, timeout calls connection handles to close, subsequently
killing the endpoint

test/manual/core.py

@@ -1,17 +1,28 @@
-from time import sleep
+import logging
+
+from rich.logging import RichHandler
+
 from dynalab_core import Core
 from dynalab_core.config import CoreConfig
 
+logging.basicConfig(
+    level=logging.DEBUG,
+    format="%(name)s  %(message)s",
+    datefmt="%H:%M:%S",
+    handlers=[RichHandler(rich_tracebacks=True, show_path=False)],
+    force=True,
+)
+log = logging.getLogger(__name__)
+
 
 config = CoreConfig(port=8765)
-print(config)
+log.info("Configured manual core on %s", config.bind_str())
 dl_core = Core(config)
 dl_core.start()
-print("started")
 
 try:
     while True:
         dl_core.wait(1)
-        print("waiting")
 except KeyboardInterrupt:
+    log.info("Received keyboard interrupt")
     dl_core.stop()