tests - BaseSpider deprecation warning fixed + pep8

Fixed some deprecation warnings, but still have a lot during tests (because of test_hubproxy.py)

```
.......................SSSSSS/home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/hubproxy.py:11: ScrapyDeprecationWarning: scrapylib.hubproxy.HubProxyMiddleware is deprecated, use scrapylib.crawlera.CrawleraMiddleware instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
./home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/crawlera.py:59: ScrapyDeprecationWarning: use_hubproxy attribute is deprecated, use crawlera_enabled instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
/home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/crawlera.py:46: ScrapyDeprecationWarning: HUBPROXY_USER setting is deprecated, use CRAWLERA_USER instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
/home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/crawlera.py:46: ScrapyDeprecationWarning: HUBPROXY_PASS setting is deprecated, use CRAWLERA_PASS instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
/home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/crawlera.py:46: ScrapyDeprecationWarning: HUBPROXY_DOWNLOAD_TIMEOUT setting is deprecated, use CRAWLERA_DOWNLOAD_TIMEOUT instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
/home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/crawlera.py:41: ScrapyDeprecationWarning: hubproxy_download_timeout attribute is deprecated, use crawlera_download_timeout instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
./home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/crawlera.py:64: ScrapyDeprecationWarning: HUBPROXY_ENABLED setting is deprecated, use CRAWLERA_ENABLED instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
../home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/crawlera.py:46: ScrapyDeprecationWarning: HUBPROXY_MAXBANS setting is deprecated, use CRAWLERA_MAXBANS instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
./home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/crawlera.py:46: ScrapyDeprecationWarning: HUBPROXY_URL setting is deprecated, use CRAWLERA_URL instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
../home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/crawlera.py:41: ScrapyDeprecationWarning: hubproxy_user attribute is deprecated, use crawlera_user instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
/home/alex/Workspace/scrapinghub/repo/scrapylib/scrapylib/crawlera.py:41: ScrapyDeprecationWarning: hubproxy_pass attribute is deprecated, use crawlera_pass instead.
  category=ScrapyDeprecationWarning, stacklevel=1)
............................

```