Add wifi manager portal (#161)

* Add Wifi manager web portal for ESP8266

#15
#83

* represent web page if MQTT failures at start

* add arduinojson library on CI and repo

* add parameter in test config for CI and correct ifdef

* add wifi manager library

* add possibility to manual setup esp8266 wifi credential

* add mqtt user and password into wifimanager

* Add MinimumWifiSignalQuality parameter

Following @ctripodi suggestion to remove AP with low signal quality

.gitmodules

@@ -28,3 +28,9 @@
 [submodule "libraries/ESP32_BLE_Arduino"]
 	path = libraries/ESP32_BLE_Arduino
 	url = git://github.com/nkolban/ESP32_BLE_Arduino.git
+[submodule "libraries/ArduinoJson"]
+	path = libraries/ArduinoJson
+	url = git://github.com/bblanchon/ArduinoJson.git
+[submodule "libraries/WifiManager"]
+	path = libraries/WifiManager
+	url = git://github.com/tzapu/WifiManager.git