Remove -nographics flag, ensure -batchmode

dist/steps/activate.sh

@@ -25,7 +25,7 @@ if [[ -n "$UNITY_LICENSE" ]] || [[ -n "$UNITY_LICENSE_FILE" ]]; then
 
   # Activate license
   ACTIVATION_OUTPUT=$(unity-editor \
-      -nographics \
+      -batchmode \
       -logFile /dev/stdout \
       -quit \
       -manualLicenseFile $FILE_PATH)
@@ -63,7 +63,6 @@ elif [[ -n "$UNITY_SERIAL" && -n "$UNITY_EMAIL" && -n "$UNITY_PASSWORD" ]]; then
   # Activate license
   unity-editor \
     -batchmode \
-    -nographics \
     -logFile /dev/stdout \
     -quit \
     -serial "$UNITY_SERIAL" \

dist/steps/build.sh

@@ -116,7 +116,7 @@ echo ""
 # Reference: https://docs.unity3d.com/2019.3/Documentation/Manual/CommandLineArguments.html
 
 unity-editor \
-  -nographics \
+  -batchmode \
   -logfile /dev/stdout \
   -quit \
   -customBuildName "$BUILD_NAME" \

dist/steps/return_license.sh

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