travis: try to fix png screenshot issue

.travis.yml

@@ -27,7 +27,7 @@ before_install:
 install:
     - ./prepare.py i386
     - make -j1 -s 1>/dev/null
-    - mkdir -p Screens
+    - mkdir -p $KIF_SCREENSHOTS
 
 script:
     - xctool -project linphone.xcodeproj -scheme linphone -sdk iphonesimulator8.1 build 1>/dev/null

Tools/imgur_upload.sh

@@ -5,14 +5,15 @@ if ! which underscore &> /dev/null; then
 	npm install -g underscore-cli
 fi
 
-cd Screens
+cd $KIF_SCREENSHOTS
+pwd
+ls
 
 if "*.png" 2>/dev/null; then
 	# Prepare location to collect delete commands
 	if test "$TRAVIS_BUILD_NUMBER" = ""; then
 		TRAVIS_BUILD_NUMBER="dev"
 	fi
-	output_dir="Screens"
 	download_cmds=""
 
 	# curl from http://imgur.com/tools/imgurbash.sh via http://imgur.com/tools