For Travis CI - add some of the excluded samples back to Emscripten CI.

Fix package upload rake task failed to skip cleanly for MinGW CI build for D3D9.
Test [ci package] for [ci only: Emscripten] again.

.travis.yml

@@ -357,17 +357,8 @@ data:
   excluded_sample:
     - 01_HelloWorld
     - 02_HelloGUI
-    - 03_Sprites
-    - 04_StaticScene
-    - 05_AnimatingScene
     - 26_ConsoleInput
     - 29_SoundSynthesis
-    - 30_LightAnimation
-    - 31_MaterialAnimation
-    - 34_DynamicGeometry
-    - 35_SignedDistanceFieldText
-    - 37_UIDrag
-    - 38_SceneAndUILoad
 
 ...
 

Rakefile

@@ -255,7 +255,7 @@ end
 desc 'Update site documentation to GitHub Pages'
 task :ci_site_update do
   # Skip when :ci rake task was skipped
-  next unless Dir.exists?('../Build')
+  next unless File.exist?('../Build/CMakeCache.txt')
   # Pull or clone
   system 'cd ../doc-Build 2>/dev/null && git pull -q -r || git clone --depth 1 -q https://github.com/urho3d/urho3d.github.io.git ../doc-Build' or abort 'Failed to pull/clone'
   # Update credits from README.md to about.md
@@ -336,7 +336,7 @@ end
 desc 'Make binary package and upload it to a designated central hosting server'
 task :ci_package_upload do
   # Skip when :ci rake task was skipped
-  next unless Dir.exists?('../Build')
+  next unless File.exist?('../Build/CMakeCache.txt')
   if ENV['XCODE']
     $configuration = 'Release'
     $testing = 0