add tox.ini

tox.ini

@@ -0,0 +1,46 @@
+[tox]
+envlist =
+    py{36,37,38}-test{,-all,-dev}
+    build_docs
+    codestyle
+requires =
+    setuptools >= 30.3.0
+    pip >= 19.3.1
+isolated_build = true
+
+[testenv]
+passenv =
+    HOME
+    DISPLAY
+    LC_ALL
+    LC_CTYPE
+    ON_TRAVIS
+changedir =
+    .tmp/{envname}
+description =
+    run tests with pytest
+deps =
+    dev: git+https://github.com/astropy/astropy#egg=astropy
+    dev: git+https://github.com/astropy/reproject#egg=reproject
+extras =
+    test
+    all: all
+commands =
+    pip freeze
+    pytest --open-files --pyargs imf {toxinidir}/docs --cov imf --cov-config={toxinidir}/.coveragerc {posargs}
+
+[testenv:build_docs]
+changedir =
+    docs
+description =
+    invoke sphinx-build to build the HTML docs
+extras =
+    docs
+commands =
+    sphinx-build -W -b html . _build/html {posargs}
+
+[testenv:codestyle]
+deps = flake8
+skip_install = true
+commands =
+    flake8 --max-line-length=100 imf