Add RUSTFLAGS=-Awarnings to runtests.sh

If there are warnings in the crate build, we should avoid them while
running each individual test, otherwise we get nonstop warnings.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

runtests.sh

@@ -10,6 +10,9 @@ here="$(realpath "$(dirname "$0")")"
 tests="$here/tests"
 flags="--quiet --release"
 
+# Disable warnings while running tests
+export RUSTFLAGS=-Awarnings
+
 echo "building"
 cargo build $flags || die "build failed"