Added gecko driver

Author: budtmo

Appium/Dockerfile

@@ -146,11 +146,13 @@ USER 1300:1301
 #===============================
 # Install basic Android drivers
 #===============================
-ENV APPIUM_DRIVER_FLUTTER_VERSION="1.14.3"
 ENV APPIUM_DRIVER_ESPRESSO_VERSION="2.20.1"
+ENV APPIUM_DRIVER_FLUTTER_VERSION="1.14.3"
+ENV APPIUM_DRIVER_GECKO_VERSION="1.1.9"
 ENV APPIUM_DRIVER_UIAUTOMATOR2_VERSION="2.14.0"
 RUN appium driver install --source=npm appium-espresso-driver@${APPIUM_DRIVER_ESPRESSO_VERSION} && \
     appium driver install --source=npm appium-flutter-driver@${APPIUM_DRIVER_FLUTTER_VERSION} && \
+    appium driver install --source=npm appium-geckodriver@${APPIUM_DRIVER_GECKO_VERSION} && \
     appium driver install --source=npm appium-uiautomator2-driver@${APPIUM_DRIVER_UIAUTOMATOR2_VERSION}
 
 #===============