Add basic smoke test for MCAP converter

Grab the latest release of the "mcap" tool, which
includes a validator for MCAP files. Then
write a simple test that generates an AOS log,
converts it to MCAP, and tests that it is correct.

Change-Id: Ia2befa535405de1110810706b76f48782064da32
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/WORKSPACE b/WORKSPACE
index 2113efe..df7ed47 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -1175,3 +1175,10 @@
     name = "com_github_nlohmann_json",
     path = "third_party/com_github_nlohmann_json",
 )
+
+http_file(
+    name = "com_github_foxglove_mcap_mcap",
+    executable = True,
+    sha256 = "cf4dfcf71e20a60406aaded03a165312c1ca535b509ead90eb1846fc598137d2",
+    urls = ["https://github.com/foxglove/mcap/releases/download/releases%2Fmcap-cli%2Fv0.0.5/mcap-linux-amd64"],
+)