travis: Save cache when compilation took very long

.travis/test_06_script_b.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2018 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+export LC_ALL=C.UTF-8
+
+cd "build/bitcoin-$HOST" || (echo "could not enter distdir build/bitcoin-$HOST"; exit 1)
+
+if [ "$RUN_UNIT_TESTS" = "true" ]; then
+  BEGIN_FOLD unit-tests
+  DOCKER_EXEC LD_LIBRARY_PATH=$TRAVIS_BUILD_DIR/depends/$HOST/lib make $MAKEJOBS check VERBOSE=1
+  END_FOLD
+fi
+
+if [ "$TRAVIS_EVENT_TYPE" = "cron" ]; then
+  extended="--extended --exclude feature_pruning"
+fi
+
+if [ "$RUN_FUNCTIONAL_TESTS" = "true" ]; then
+  BEGIN_FOLD functional-tests
+  DOCKER_EXEC test/functional/test_runner.py --ci --combinedlogslen=4000 --coverage --quiet --failfast ${extended}
+  END_FOLD
+fi