Configure build+test matrix for GitLab CI:

* Disable parallel tests for address sanitizer
* Improve caching
* Prefer Ninja builds because they are faster

bin/ci/test.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+
+set -o xtrace
+set -o errexit
+
+# Set to 'true' to run the known "manual" tests in rippled.
+MANUAL_TESTS=${MANUAL_TESTS:-false}
+# The maximum number of concurrent tests.
+CONCURRENT_TESTS=${CONCURRENT_TESTS:-$(nproc)}
+# The path to rippled.
+RIPPLED=${RIPPLED:-build/rippled}
+# Additional arguments to rippled.
+RIPPLED_ARGS=${RIPPLED_ARGS:-}
+
+function join_by { local IFS="$1"; shift; echo "$*"; }
+
+declare -a manual_tests=(
+  'beast.chrono.abstract_clock'
+  'beast.unit_test.print'
+  'ripple.NodeStore.Timing'
+  'ripple.app.Flow_manual'
+  'ripple.app.NoRippleCheckLimits'
+  'ripple.app.PayStrandAllPairs'
+  'ripple.consensus.ByzantineFailureSim'
+  'ripple.consensus.DistributedValidators'
+  'ripple.consensus.ScaleFreeSim'
+  'ripple.ripple_data.digest'
+  'ripple.tx.CrossingLimits'
+  'ripple.tx.FindOversizeCross'
+  'ripple.tx.Offer_manual'
+  'ripple.tx.OversizeMeta'
+  'ripple.tx.PlumpBook'
+)
+
+if [[ ${MANUAL_TESTS} == 'true' ]]; then
+  RIPPLED_ARGS+=" --unittest=$(join_by , "${manual_tests[@]}")"
+else
+  RIPPLED_ARGS+=" --unittest --quiet --unittest-log"
+fi
+RIPPLED_ARGS+=" --unittest-jobs ${CONCURRENT_TESTS}"
+
+${RIPPLED} ${RIPPLED_ARGS}