====/igg/getlesson====
Retrieve the current data of a lesson

parameters:
|auth	|the authorisation code you received from Intogolf BV (mandatory)|
|relnr	|the id of the golfer that is currently logged in (mandatory)|
|relkey	|the hash key that was provided upon login (mandatory if relnr>0)|
|lesnr	|id of booking (mandatory)|


example: https://backend.ikgagolfen.nl/igg/getlesson?auth=<your authorisation code>&lesnr=167077&relnr=707025&relkey=a8d2aaaef4131d033d60cdfd0bfe9804

result (if booking not canceled):
<code>{
  "getlesson": [
    {
      "crsnr": 1,
      "crsshortname": "Intogolf",
      "crsname": "Intogolf BV",
      "lesnr": 167077,
      "lesdate": "20121001",
      "lestimefrom": 720,
      "lestimeto": 775,
      "pronr": 7493,
      "proname": "Hit Better",
      "pltnr": 1,
      "pltname": "uur les",
      "canceled": 0,
      "players": [
        {
          "plc": 271411,
          "relnr": 707025,
          "plcname": "Vries, Fred de"
        },
        {
          "plc": 271412,
          "relnr": 0,
          "plcname": "golfer 2"
        }
      ]
    }
  ]
}</code>

result if canceled:
<code>{
  "getlesson": [
    {
      "crsnr": 1,
      "crsshortname": "Intogolf",
      "crsname": "Intogolf BV",
      "lesnr": 167075,
      "lesdate": "20121001",
      "lestimefrom": 720,
      "lestimeto": 775,
      "pronr": 7493,
      "proname": "Hit Better",
      "pltnr": 1,
      "pltname": "uur les",
      "canceled": 1,
      "players": [

      ]
    }
  ]
}</code>

if a wrong authorisation code is provided, the backend will return “no authorisation”