Support for python2.6. Should fix master for #127

.travis.yml

@@ -25,6 +25,7 @@ install:
     - export PATH=$PATH:$PWD
     - cd ..
 before_script:
+    - if [ $(python --version) -lt 2.7 ]; then env pip install unittest2; fi
     - if [ $(python --version) -gt 2.6 ]; then env pip install biopython; fi
     - env python tests/data/download_gene_fasta.py
 script: nosetests --with-coverage --cover-package=pyfaidx

tests/test_Fasta_bgzip.py

@@ -1,7 +1,10 @@
 import os
 from pyfaidx import Fasta, Faidx, UnsupportedCompressionFormat, FetchError
 from itertools import chain
-from unittest import TestCase, expectedFailure
+try:
+    from unittest import TestCase, expectedFailure
+except ImportError:
+    from unittest2 import TestCase, expectedFailure # python2.6
 from nose.tools import raises
 from nose.plugins.skip import SkipTest
 
@@ -20,7 +23,7 @@ def tearDown(self):
             os.remove('data/genes.fasta.gz.fai')
         except EnvironmentError:
             pass  # some tests may delete this file
-            
+
     @expectedFailure
     def test_build_issue_126(self):
         """ Samtools BGZF index should be identical to pyfaidx BGZF index """