Travis CI: Drop the EOL Python 3.4 and add 3.7 (keon#513)

* Travis CI: Drop the EOL Python 3.4 and add 3.7

* Tox.ini: Travis CI: Drop the EOL py34

.travis.yml

@@ -1,16 +1,17 @@
 group: travis_latest
+dist: xenial  # Travis CI's default distro
 language: python
 cache:
   directories:
     - $HOME/.cache/pip
 matrix:
     include:
-        - python: 3.4
-          env: TOX_ENV=py34
         - python: 3.5
-          env: TOX_ENV=py35,coverage
+          env: TOX_ENV=py35
         - python: 3.6
           env: TOX_ENV=py36
+        - python: 3.7
+          env: TOX_ENV=py37,coverage
 install:
     - pip install -r test_requirements.txt
 before_script:
@@ -20,10 +21,10 @@ before_script:
     - flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
 script:
     # Check python install package
-    - pip3 install -e .
+    - pip install -e .
     - tox -e $TOX_ENV
     # Check python uninstall package
-    - pip3 uninstall -y algorithms
+    - pip uninstall -y algorithms
 notifications:
     on_success: change
     on_failure: change  # `always` will be the setting once code changes slow down

tox.ini

@@ -1,14 +1,13 @@
 [tox]
 envlist =
-    py34
     py35
     py36
+    py37
     coverage
 
 [testenv]
 passenv = TRAVIS TRAVIS_*
 basepython =
-    py34: python3.4
     py35: python3.5
     py36: python3.6
     py37: python3.7
@@ -20,30 +19,30 @@ commands =
     coverage report -m
     coveralls
 
-[testenv:py34]
+[testenv:py35]
 passenv = CI TRAVIS TRAVIS_*
 basepython =
-    python3.4
+    python3.5
 deps =
     pytest
 commands =
     python3 -m unittest discover tests
     python3 -m pytest tests
 
-[testenv:py35]
+[testenv:py36]
 passenv = CI TRAVIS TRAVIS_*
 basepython =
-    python3.5
+    python3.6
 deps =
     pytest
 commands =
     python3 -m unittest discover tests
     python3 -m pytest tests
 
-[testenv:py36]
+[testenv:py37]
 passenv = CI TRAVIS TRAVIS_*
 basepython =
-    python3.6
+    python3.7
 deps =
     pytest
 commands =
@@ -54,7 +53,7 @@ commands =
 passenv = CI TRAVIS TRAVIS_*
 skip_install = True
 basepython =
-    python3.5
+    python3.7
 commands =
     coverage run --source=tests,algorithms -m unittest discover tests
     coverage report -m