add system load module

examples/config.test.json

@@ -7,6 +7,11 @@
             "type":"uptime",
             "freq":"30",
             "args":{}
+        },
+        {
+            "type":"load",
+            "freq":"30",
+            "args":{}
         }
     ]
 }

pymonitor/monitors/load.py

@@ -0,0 +1,28 @@
+def load():
+    with open("/proc/loadavg", "r") as f:
+        m1, m5, m15, procs, pid = f.read().strip().split(" ")
+        return {
+            "load_1m": m1,
+            "load_5m": m5,
+            "load_15m":m15
+        }
+
+mapping = {
+    "load": {
+        "properties": {
+            "load_15m": {
+                "type": "double"
+            },
+            "load_5m": {
+                "type": "double"
+            },
+            "load_1m": {
+                "type": "double"
+            }
+        }
+    }
+}
+
+if __name__ == '__main__':
+    avg = load()
+    print(' '.join([avg["load_1m"], avg["load_5m"], avg["load_15m"]]))