Add a test for rpm

The test file is taken from:

```bash
❯ wget https://download-ib01.fedoraproject.org/pub/epel/7/x86_64/Packages/b/bdsync-0.11.2-1.el7.x86_64.rpm
```

Author: noahp

Dockerfile

@@ -18,6 +18,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     python2.7 \
     python3-pip \
     python3.8 \
+    rpm2cpio \
     unrar \
     unzip \
     wget \

tests/test.rpm

@@ -908,3 +908,10 @@
     zip
     zst
     zstd
+
+- name: rpm
+  filenames: test.rpm
+  baseline: |
+    mkdir test
+    cd test
+    rpm2cpio ../$1 | cpio -i --make-directories --quiet --no-absolute-filenames