Ble scanner (#976)

* Added ble_scanner component

* ble_scanner: time.h changed to ctime

* ble_scanner: Test added.

* ble_scanner: fixed code formatting.

* Removed duplicate binary sensor tests from test2 and test3 to decrease memory requirements.

* Removed another duplicate test from test2.yaml and moved stepper test to yaml3.yaml to reduce memory requirements of test2.yaml.

* Reverted the last stepper test change

* Moved some sensor tests from test2.yaml to test3.yaml to save memory.

* Moved ruuvitag back to test2.yaml as it requires component esp32_ble_tracker.

* removed apds9960 as it is duplicated

Co-authored-by: Guillermo Ruffino <glm.net@gmail.com>

esphome/components/ble_scanner/text_sensor.py

@@ -0,0 +1,22 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import text_sensor, esp32_ble_tracker
+from esphome.const import CONF_ID
+
+DEPENDENCIES = ['esp32_ble_tracker']
+
+ble_scanner_ns = cg.esphome_ns.namespace('ble_scanner')
+BLEScanner = ble_scanner_ns.class_('BLEScanner', text_sensor.TextSensor, cg.Component,
+                                   esp32_ble_tracker.ESPBTDeviceListener)
+
+CONFIG_SCHEMA = cv.All(text_sensor.TEXT_SENSOR_SCHEMA.extend({
+    cv.GenerateID(): cv.declare_id(BLEScanner),
+}).extend(esp32_ble_tracker.ESP_BLE_DEVICE_SCHEMA).extend(
+    cv.COMPONENT_SCHEMA))
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+    yield esp32_ble_tracker.register_ble_device(var, config)
+    yield text_sensor.register_text_sensor(var, config)