FIX remove sampling_type from base class (#338)

Author: glemaitre

imblearn/base.py

@@ -131,10 +131,9 @@ class BaseSampler(SamplerMixin):
  instead.
  """
 
- def __init__(self, ratio='auto', random_state=None, sampling_type=None):
+ def __init__(self, ratio='auto', random_state=None):
  self.ratio = ratio
  self.random_state = random_state
- self.sampling_type = sampling_type
  self.logger = logging.getLogger(__name__)
 
  def fit(self, X, y):