Exclude trouble utf-8 spec file name from npm

Turns out old Java API struggles with certain UTF-8 characters.

https://github.com/dlmanning/gulp-sass/issues/529
https://github.com/sass/node-sass/issues/1699

This is affecting JVM based build systems like Jenkins

https://issues.jenkins-ci.org/browse/JENKINS-12610
https://issues.jenkins-ci.org/browse/JENKINS-33478

.gitignore

@@ -10,4 +10,5 @@ test/lcov-report
 test/lcov.info
 test/fixtures/watching-css-out-01
 test/fixtures/watching-css-out-02
+test/fixtures/spec/spec/libsass/Sáss-UŢF8
 coverage