Merge remote-tracking branch 'vivek/master'

* vivek/master:
  Updated failing test cases, changes to to_fasta
  Updated the unit test cases to fix Travis fail
  Eliminate sequence name collisions
  Removed unused variable and typing mistake
  Added unit test for uniquification of sequence ids
  Added unit test for to_fasta

close #118

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>