add comment explaining large condition
fix imports in compute python
rename seq/Sequence, l/seq
Use miniconda for conda rather than pip

Recommended by asmeurer

See http://conda.pydata.org/docs/travis.html
Merge pull request #273 from mrocklin/working

Various fixes, often in SQL
sql extend avoids coerce_row_to_dict call
change order of reduceby inputs
increase size of dynd coercion block
don't use get in inner csv loop