Run ecdsa-psbt example in test script

We just added a PSBT example file, run it from CI for all test runs.

contrib/test.sh

@@ -62,6 +62,8 @@ do
     cargo test --verbose --features="$feature"
 done
 
+cargo run --example ecdsa-psbt --features=bitcoinconsensus
+
 # Build the docs if told to (this only works with the nightly toolchain)
 if [ "$DO_DOCS" = true ]; then
     RUSTDOCFLAGS="--cfg docsrs" cargo +nightly rustdoc --features="$FEATURES" -- -D rustdoc::broken-intra-doc-links