Procyclingstats

Changes:
- Winners of stages of a race are parsed from `Race.stages_winners` method, not from `Race.stages` method as previously.
- `Stage.avg_speed_winner`, `Stage.avg_temperature`, `Stage.start_time`, `Stage.race_category` metohds added: https://github.com/themm1/procyclingstats/pull/19
- `Rider.image_url` method added: https://github.com/themm1/procyclingstats/issues/22
- Bonus is parsed in time format (`H:MM:SS`, not as number of seconds): https://github.com/themm1/procyclingstats/pull/19

Issues fixed:
- Bike parsing `Team.bike()` method fixed: https://github.com/themm1/procyclingstats/pull/25

Issues fixed:
- Errors caused by invalid times on PCS website: https://github.com/themm1/procyclingstats/issues/15
- ``Team.riders()`` method parsing errors: https://github.com/themm1/procyclingstats/issues/16

Changes:
- ``Rider.points_per_speciality`` method added: https://github.com/themm1/procyclingstats/pull/13

Issues fixed:
- Stages with no profile score don't cause parsing errors: https://github.com/themm1/procyclingstats/issues/11
- Parsing for PCS one day races ranking fixed: https://github.com/themm1/procyclingstats/issues/12
- Riders that didn't finished TTT aren't listed in the TTT results, so parsing error isn't raised: https://github.com/themm1/procyclingstats/issues/14

Install this version with ``pip install procyclingstats==0.1.6``.
Changes:
- ``Rider.weight`` method returns a float now, since some riders weights are given as floats

Install this version with ``pip install procyclingstats==0.1.5``.
Due to difficult maintenance of ``Scraper.normalized_relative_url`` and URL validating, we had to remove these features.

Changes:
- HTML parsing bugs fixed
- ``rider_number`` field added to ``Stage`` table parsing methods
- Winners of the stages and their nationalities added to table returned by ``Race.stages``
- ``distance`` field removed from table returned by ``Race.stages``
- ``Scraper.normalized_relative_url`` method removed
- ``Scraper.__eq__`` method removed (it's not possible to compare objects anymore)
- URL validating is no longer available