Tests for matrix variable

.drone.yml

@@ -7,7 +7,7 @@ steps:
   - name: fetch ip
     image: cburki/mosquitto-clients
     commands:
-      - echo "${HOSTNAME}"
+      - echo "Hostname is: ---${HOSTNAME}--- $HOSTNAME ... \$HOSTNAME ... \${HOSTNAME} +++ $\{HOSTNAME\}"
       - mosquitto_sub -h raum.ctdo.de -t "homie/${HOSTNAME}/\$localip" -C 1 | tr -d '\n'
       - mosquitto_sub -h raum.ctdo.de -t "homie/${HOSTNAME}/\$localip" -C 1 | tr -d '\n' >lastknownip
       - cat "lastknownip"
@@ -49,8 +49,8 @@ steps:
 ### https://0-8-0.docs.drone.io/matrix-builds/
 ###
 
-
 matrix:
-  HOSTNAME:
-    - blinky1
-    - blinky2
+  include:
+    HOSTNAME:
+      - blinky1
+      - blinky2