TEST: Abstract out directory/file deletion methods.
MAINT: Remove unused blob and b64_blob attributes.
TEST: Verify base64 return values after decoding.
BUG: Convert to bytes before comparing binary blobs.
STY: Define dirs as a single expression.
TEST: Add a non-notebook file to directory test.
MAINT: Unicode literal in assertDictContainsSubset
Merge pull request #20 from quantopian/contents-test-reuse-4

Contents test reuse 4