message: Use ninja in test_coverage.sh
diff: sync=${1}
  deps_suffix="${2}"
  -nprocs=1
  -if [ "$(uname)" = "Linux" ]; then
  - nprocs=$(grep -c ^processor /proc/cpuinfo)
  -fi
  -
  : ${OPENSSL_ROOT_DIR:=/usr/local}
  set -e
  @@ -30,7 +25,7 @@ if [ "${sync}" = "sync" ]; then
  cmake_flags="${cmake_flags} -DREALM_ENABLE_SYNC=1 -DREALM_ENABLE_SERVER=1 -DOPENSSL_ROOT_DIR=${OPENSSL_ROOT_DIR}"
  fi
  -cmake ${cmake_flags} -DCMAKE_BUILD_TYPE=Coverage -DDEPENDENCIES_FILE="dependencies${deps_suffix}.list" ..
  -make VERBOSE=1 -j${nprocs} generate-coverage-cobertura
  +cmake ${cmake_flags} -G Ninja -DCMAKE_BUILD_TYPE=Coverage -DDEPENDENCIES_FILE="dependencies${deps_suffix}.list" ..
  +ninja -v generate-coverage-cobertura
  find $TMPDIR -name 'realm*' -exec rm -rf "{}" \+ || true
  