Remove bad test

Test was verifying that bad Unicode caused the parser to choke -- this
shouldn't be tested, and now that the parser is a bit more robust it
fails.

Also remove the data file on which it depends.
Add Python 3.4 as a Travis target
Fix Urllib2Fetcher to deal with urlopen() errors

...well, more correctly anyhow, by wrapping the appropriate ones
in its own response type.
Clearer argument name
Note the situation in a comment since no fix is made
Cleanup code
Define openid.association.Association.secret as bytes
Fix tests for openid.association.Association

Expect secrets as bytes, add a better handle to the test association.
Cleanup openid.test.storetest

Organize imports, add warnings for tests that are skipped because
the relevant libraries aren't present, clean up coding style, and
update the SQLite test to use sqlite3
Simplify code, add comments
Update openid.store.sqlstore for Python 3