add a logline stating the architecture for binary package

Since we can't seem to figure out where we're going wrong, I thought I'd
just add verbose logging here and hope it helps with debugging the new
feature, which aims to reduce the number of i386 tests queued.

britney2/policies/autopkgtest.py

@@ -708,6 +708,7 @@ class AutopkgtestPolicy(BasePolicy):
                 all_binaries_arch_all = True
                 for package_name in binaries_info.keys():
                     bin_arch = binaries_info[package_name].architecture or 'all'
+                    self.logger.info('Binary has arch %s for binary %s', bin_arch, package_name)
                     if bin_arch != 'all':
                         all_binaries_arch_all = False
                         break