travis-ci: skip Uygher (ug) in Ubuntu/trusty tests, gettext is too old

Traceback (most recent call last):
  File "./setup.py", line 97, in <module>
    'Topic :: Utilities',
  File "/usr/lib/python3.4/distutils/core.py", line 148, in setup
    dist.run_commands()
  File "/usr/lib/python3.4/distutils/dist.py", line 955, in run_commands
    self.run_command(cmd)
  File "/usr/lib/python3.4/distutils/dist.py", line 974, in run_command
    cmd_obj.run()
  File "/usr/lib/python3/dist-packages/babel/messages/frontend.py", line 133, in run
    catalog = read_po(infile, locale)
  File "/usr/lib/python3/dist-packages/babel/messages/pofile.py", line 121, in read_po
    catalog = Catalog(locale=locale, domain=domain, charset=charset)
  File "/usr/lib/python3/dist-packages/babel/messages/catalog.py", line 247, in __init__
    locale = Locale.parse(locale)
  File "/usr/lib/python3/dist-packages/babel/core.py", line 313, in parse
    raise UnknownLocaleError(input_id)
babel.core.UnknownLocaleError: unknown locale 'ug'

.travis.yml

@@ -46,6 +46,10 @@ android:
 #   https://blogs.oracle.com/java-platform-group/oracle-jre-will-no-longer-trust-md5-signed-code-by-default
 #   https://opsech.io/posts/2017/Jun/09/openjdk-april-2017-security-update-131-8u131-and-md5-signed-jars.html
 install:
+  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
+      echo "Skipping Uyghur locale, this has too old a gettext to support it";
+      rm -rf locale/ug;
+    fi
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
       set -x;
       brew update > /dev/null;