Actually test futures builds

Currently the BP `futures` tests rely on `std`. In order to actually
have them run, we should enable `std`, i.e., remove
`--no-default-features`.

Author: tnull

ci/ci-tests.sh

@@ -86,7 +86,7 @@ fi
 
 echo -e "\n\nTest futures builds"
 pushd lightning-background-processor
-cargo test --verbose --color always --no-default-features --features futures
+cargo test --verbose --color always --features futures
 popd
 
 if [ "$RUSTC_MINOR_VERSION" -gt 55 ]; then