Moves coverage report generation to pytest from nosetests

Uses pytest instead of py.test for all test runners
Uses Python 3.7 instead of Python 2.7 for the coverage runner

Author: palnabarun

.travis.yml

@@ -14,7 +14,7 @@ matrix:
        env: TOXENV=update-pycodestyle
      - python: 3.7
        env: TOXENV=docs
-     - python: 2.7
+     - python: 3.7
        env: TOXENV=coverage,codecov
      - python: 3.5
        env: TOXENV=py35

tox.ini

@@ -9,7 +9,7 @@ deps = -r{toxinidir}/test-requirements.txt
        -r{toxinidir}/requirements.txt
 commands =
    python -V
-   py.test -vvv -s --ignore=kubernetes/e2e_test
+   pytest -vvv -s --ignore=kubernetes/e2e_test
 
 [testenv:docs]
 commands =
@@ -22,27 +22,27 @@ commands =
 [testenv:py27-functional]
 commands =
    python -V
-   {toxinidir}/scripts/kube-init.sh py.test -vvv -s []
+   {toxinidir}/scripts/kube-init.sh pytest -vvv -s []
 
 [testenv:py35-functional]
 commands =
    python -V
-   {toxinidir}/scripts/kube-init.sh py.test -vvv -s []
+   {toxinidir}/scripts/kube-init.sh pytest -vvv -s []
 
 [testenv:py36-functional]
 commands =
    python -V
-   {toxinidir}/scripts/kube-init.sh py.test -vvv -s []
+   {toxinidir}/scripts/kube-init.sh pytest -vvv -s []
 
 [testenv:py37-functional]
 commands =
    python -V
-   {toxinidir}/scripts/kube-init.sh py.test -vvv -s []
+   {toxinidir}/scripts/kube-init.sh pytest -vvv -s []
 
 [testenv:coverage]
 commands =
    python -V
-   nosetests --with-coverage --cover-package=kubernetes.config,kubernetes.watch --cover-tests
+   pytest --ignore=kubernetes/e2e_test --cov=kubernetes/watch --cov=kubernetes/config
 
 [testenv:codecov]
 commands =