Remove duplicate flag batch-mode (#173)

action/steps/activate.sh

@@ -25,7 +25,6 @@ if [[ -n "$UNITY_LICENSE" ]] || [[ -n "$UNITY_LICENSE_FILE" ]]; then
 
   # Activate license
   ACTIVATION_OUTPUT=$(unity-editor \
-      -batchmode \
       -nographics \
       -logFile /dev/stdout \
       -quit \

action/steps/build.sh

@@ -109,7 +109,6 @@ echo "###########################"
 echo ""
 
 unity-editor \
-  -batchmode \
   -nographics \
   -logfile /dev/stdout \
   -quit \

action/steps/return_license.sh

@@ -7,7 +7,6 @@ if [[ -n "$UNITY_SERIAL" ]]; then
   # This will return the license that is currently in use.
   #
   unity-editor \
-    -batchmode \
     -nographics \
     -logFile /dev/stdout \
     -quit \