travis: Increase travis_wait time while verifying commits

ken2812221 · ken2812221 · commit 51ed05a2b9c1 · 2018-06-12T15:46:51.000Z
From https://travis-ci.org/ken2812221/bitcoin-verify-commits/builds I have run vecify-commits.py nightly on travis, as you can see that 30 minutes is not enough, it took 30-50 minutes to run the script with no extra options. So change it to 50 minutes would be better.
diff --git a/.travis.yml b/.travis.yml
@@ -104,5 +104,5 @@ jobs:
         - test/lint/lint-all.sh
         - if [ "$TRAVIS_REPO_SLUG" = "bitcoin/bitcoin" -a "$TRAVIS_EVENT_TYPE" = "cron" ]; then
               while read LINE; do travis_retry gpg --keyserver hkp://subset.pool.sks-keyservers.net --recv-keys $LINE; done < contrib/verify-commits/trusted-keys &&
-              travis_wait 30 contrib/verify-commits/verify-commits.py;
+              travis_wait 50 contrib/verify-commits/verify-commits.py;
           fi
