fixed requirements and working on TracisCI and Coveralls integration

.travis.yml

@@ -2,10 +2,14 @@ language: python
 python: 2.7
 install:
   - pip install tox
+  - pip install coveralls
 env:
   - TOX_ENV=py26
   - TOX_ENV=py27
   - TOX_ENV=py32
   - TOX_ENV=py33
+  - TOX_ENV=coverage
 script:
-  - tox -e $TOX_ENV
+  - tox
+after_success:
+  - coveralls

requirements.txt

@@ -1 +1,3 @@
-six
+# workaround for problematic nose2 requirements
+six>=1.1,<1.4
+

test_requirements.txt

@@ -1,3 +1 @@
-# workaround for problematic nose2 requirements
-six>=1.1,<1.4
 nose2

tox.ini

@@ -43,3 +43,11 @@ deps =
 deps =
     {[testenv]deps}
     biopython
+
+[testenv:coverage]
+basepython = python2.7
+deps =
+    {[testenv:py27]deps}
+    coverage
+commands =
+    coverage run --branch -m nose2