tests: Avoid relying on setup data (test_image).
tests: Avoid relying on setup data (test_image).

It is better for the verifying code to just explicitly
ensure that the exported file bytes match the bytes
in the test image.  This introduces a tiny bit more
of I/O.

eeshangarg/zulip,kou/zulip,zulip/zulip,eeshangarg/zulip,rht/zulip,kou/zulip,andersk/zulip,kou/zulip,eeshangarg/zulip,rht/zulip,kou/zulip,eeshangarg/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,andersk/zulip,rht/zulip,andersk/zulip,rht/zulip,zulip/zulip,rht/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,rht/zulip,kou/zulip,rht/zulip,andersk/zulip,zulip/zulip,zulip/zulip,zulip/zulip,andersk/zulip,andersk/zulip,andersk/zulip,eeshangarg/zulip