Basic initial implementation

This is a base implementation which does following
1. create a daemon,
2. parse config file and create a virtual sensor object
3. create list of virtual sensors for given config.
4. Creates a systemd unit file

It currently supports constant params only and dbus params will be in
follow up patch.

Signed-off-by: Vijay Khemka <vijaykhemka@fb.com>
Change-Id: I89b2ffb8bff67bdbb3033071cba9f6e565a9af6e
diff --git a/virtual_sensor_config.json b/virtual_sensor_config.json
new file mode 100644
index 0000000..a394fae
--- /dev/null
+++ b/virtual_sensor_config.json
@@ -0,0 +1,46 @@
+[
+	{
+		"Desc" :
+		{
+			"Name" : "Virtual_Inlet_Temp",
+			"SensorType" : "temperature"
+		},
+		"Threshold" :
+		{
+			"CriticalHigh": 90,
+			"CriticalLow": 20,
+			"WarningHigh": 70,
+			"WarningLow": 30
+		},
+		"Params":
+		{
+			"ConstParam" :
+			[
+				{
+					"ParamName" : "P1",
+					"Value" : 1.1
+				}
+			],
+			"DbusParam" :
+			[
+				{
+					"ParamName" : "P2",
+					"Desc" :
+					{
+						"Name" : "MB_INLET_TEMP",
+						"SensorType" : "temperature"
+					}
+				},
+				{
+					"ParamName" : "P3",
+					"Desc" :
+					{
+						"Name" : "MB_FAN0_TACH",
+						"SensorType" : "fan_tach"
+					}
+				}
+			]
+		},
+		"Expression" : "P1 * (P2 + 5 - P3 * 0.01)"
+	}
+]