dump_devinfo improvements (#657)

* dump_devinfo improvements

* Scrub only the last three bytes for mac addresses
* Add --target to allow creating fixtures based on discovery
* Save fixtures directly to correct location, add --basedir to allow defining the location of repository root
* Add --autosave to disable prompting for saving

* Update fixtures for devices I have

* Add fixture for HS110 hw 4.0 fw 1.0.4

* Improve help strings

* Fix tests

* Update devtools README

* Default to discovery if no host/target given

kasa/tests/fixtures/KP115(EU)_1.0_1.0.16.json

@@ -1,17 +1,17 @@
 {
     "emeter": {
         "get_realtime": {
-            "current_ma": 0,
+            "current_ma": 296,
             "err_code": 0,
-            "power_mw": 0,
-            "total_wh": 0,
-            "voltage_mv": 231561
+            "power_mw": 63499,
+            "total_wh": 12068,
+            "voltage_mv": 230577
         }
     },
     "system": {
         "get_sysinfo": {
             "active_mode": "none",
-            "alias": "TP-LINK_Smart Plug_330B",
+            "alias": "#MASKED_NAME#",
             "dev_name": "Smart Wi-Fi Plug Mini",
             "deviceId": "0000000000000000000000000000000000000000",
             "err_code": 0,
@@ -20,9 +20,9 @@
             "hw_ver": "1.0",
             "icon_hash": "",
             "latitude_i": 0,
-            "led_off": 0,
+            "led_off": 1,
             "longitude_i": 0,
-            "mac": "00:00:00:00:00:00",
+            "mac": "C0:06:C3:00:00:00",
             "mic_type": "IOT.SMARTPLUGSWITCH",
             "model": "KP115(EU)",
             "next_action": {
@@ -31,9 +31,9 @@
             "ntc_state": 0,
             "obd_src": "tplink",
             "oemId": "00000000000000000000000000000000",
-            "on_time": 197,
+            "on_time": 2078998,
             "relay_state": 1,
-            "rssi": -70,
+            "rssi": -49,
             "status": "new",
             "sw_ver": "1.0.16 Build 210205 Rel.163735",
             "updating": 0