Update AppVeyor to run sass-spec against the 3.5 language version

I missed some reference to 3.5 in #2272

Author: xzyfer

GNUmakefile.am

@@ -57,7 +57,7 @@ TESTS = \
 	$(SASS_SPEC_PATH)/spec/scss-tests \
 	$(SASS_SPEC_PATH)/spec/types
 
-SASS_TEST_FLAGS = -V 3.4 --impl libsass
+SASS_TEST_FLAGS = -V 3.5 --impl libsass
 LOG_DRIVER = env AM_TAP_AWK='$(AWK)' $(SHELL) ./script/tap-driver
 AM_LOG_FLAGS = -c ./tester $(LOG_FLAGS)
 if USE_TAP

appveyor.yml

@@ -65,7 +65,7 @@ test_script:
       }
       $env:TargetPath = Join-Path $pwd.Path $env:TargetPath
       If (Test-Path "$env:TargetPath") {
-        ruby sass-spec/sass-spec.rb -V 3.4 --probe-todo --impl libsass -c $env:TargetPath -s sass-spec/spec
+        ruby sass-spec/sass-spec.rb -V 3.5 --probe-todo --impl libsass -c $env:TargetPath -s sass-spec/spec
         if(-not($?)) {
           echo "sass-spec tests failed"
           exit 1

docs/build-on-windows.md

@@ -130,7 +130,7 @@ cd libsass
 REM set PATH=%PATH%;%PROGRAMFILES%\MSBuild\12.0\Bin
 msbuild /m:4 /p:Configuration=Release win\libsass.sln
 REM running the spec test-suite manually (needs ruby and minitest gem)
-ruby sass-spec\sass-spec.rb -V 3.4 -c win\bin\sassc.exe -s --impl libsass sass-spec/spec
+ruby sass-spec\sass-spec.rb -V 3.5 -c win\bin\sassc.exe -s --impl libsass sass-spec/spec
 cd ..
 ```