added disagreement metrics: vote and euclidean distance

Signed-off-by: dzhuang3 <dzhuang3@hawk.iit.edu>
Revert "added disagreement metrics: vote and euclidean distance"

This reverts commit aae2bcbde85e0309b254a47b471236e1ef4afb36.

Signed-off-by: dzhuang3 <dzhuang3@hawk.iit.edu>
Merge branch 'master' of https://github.com/dzhuang2/active_learn
added euclidean and vote for disagreemnt strategy
added cover + uncPM approach

Signed-off-by: dzhuang3 <dzhuang3@hawk.iit.edu>