Allow lint failures for now; use py35 for lint and coverage.

.travis.yml

@@ -4,22 +4,23 @@ language: python
 cache: pip
 
 # Tox cannot install pythons, so we set 3.5 as default, use 3.4 already
-# available in container and then include 3.6 in matrix.
+# available in container, and then include 3.6 in matrix.
 python:
   - 3.5
 
 env:
-  - TOXENV=py34
-  - TOXENV=py35
+  matrix:
+    - TOXENV=py34
+    - TOXENV=py35
 
 matrix:
   include:
     - python: 3.6
       env: TOXENV=py36
-    - python: 3.4  # i.e. skip installing 3.5
-      env: TOXENV=lint
-    - python: 3.4
-      env: TOXENV=coverage34
+    - env: TOXENV=coverage
+    - env: TOXENV=lint
+  allow_failures:
+    - env: TOXENV=lint
 
 install:
   - pip install tox

tox.ini

@@ -12,16 +12,7 @@ commands =
 deps = coverage
 
 [testenv:coverage]
-basepython = python3.4
-skip_install = true
-commands =
-    coverage combine
-    coverage report
-deps =
-    coverage
-
-[testenv:coverage34]
-basepython = python3.4
+basepython = python3.5
 install_command =
     pip install {opts} {packages}
 ignore_errors = True
@@ -34,8 +25,17 @@ commands =
 deps =
     coverage
 
+[testenv:combine_coverage]
+basepython = python3.5
+skip_install = true
+commands =
+    coverage combine
+    coverage report
+deps =
+    coverage
+
 [testenv:lint]
-basepython = python3.4
+basepython = python3.5
 skip_install = true
 commands =
     flake8