fix travis

Author: lohanidamodar

.travis.yml

@@ -5,9 +5,9 @@ dart: stable
 os: linux
 
 install:
-- mkdir -p  ~/.pub-cache
+- mkdir -p  ~/.config/dart
 - |
-  cat <<EOF > ~/.pub-cache/credentials.json
+  cat <<EOF > ~/.config/dart/pub-credentials.json
     {
       "accessToken":"$PUB_ACCESS_TOKEN",
       "refreshToken":"$PUB_REFRESH_TOKEN",
@@ -19,6 +19,6 @@ install:
 deploy:
   provider: script
   skip_cleanup: true
-  script: dart format ./lib/ && pub publish -f
+  script: dart format ./lib/ && dart pub publish -f
   on:
     tags: true