patch 8.0.1693: xxd is excluded from coverage statistics

Problem:    Xxd is excluded from coverage statistics.
Solution:   Don't skip the xxd directory. (Christian Brabandt)
diff --git a/.travis.yml b/.travis.yml
index a2b074b..98f0838 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -108,7 +108,7 @@
   - if [ -n "$err" ]; then exit 1; fi
 
 after_success:
-  - if [ "$COVERAGE" = "yes" ]; then ~/.local/bin/coveralls -b $SRCDIR -x .xs -e ${SRCDIR}/xxd -e ${SRCDIR}/if_perl.c --encodings utf-8 latin-1 EUC-KR; fi
+  - if [ "$COVERAGE" = "yes" ]; then ~/.local/bin/coveralls -b $SRCDIR -x .xs -e ${SRCDIR}/if_perl.c --encodings utf-8 latin-1 EUC-KR; fi
   - if [ "$COVERAGE" = "yes" ]; then  cd $SRCDIR && bash <(curl -s https://codecov.io/bash) ; fi
 
 # vim:set sts=2 sw=2 tw=0 et: