Senado Collector now downloads a file that  has all records in a year. This way, it''s better than downloading the csv file for every Legislator in all the Mandate years.

 Pandas library is now used for processing  csv files.

Some code style changes.
BaseCollector now uses requests (python-requests.org). This way, the code is cleaner, we use less modules and encoding problems are solved too.

Other than that, the number of maximum tries, the timeout and sleep timer are class members now, and can be set in each Collector.

Some code style changes.
Merge pull request #17 from luciocorrea/basecollector-requests

BaseCollector now uses requests (python-requests.org). This way, the cod...
Merge pull request #18 from luciocorrea/optimize-senadocollector

Conflicts:
	requirements.txt
Senado: force windows-1252 encoding for CSV, since chardet is misdetecting it
Tests