Python 2/3 compatibility and make able to standalone install inside virtualenv

.gitignore

@@ -1,6 +1,68 @@
 .idea
 .*.swp
-*.pyc
 build/
 smime.egg-info/
 dist/
+.pytest_cache/
+.coverage
+
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+develop-eggs/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+.hypothesis/
+
+# Translations
+*.mo
+*.pot
+# dotenv
+.env
+
+# virtualenv
+.venv
+venv/
+ENV/
+
+# editor
+.idea
+.vscode
+*.sublime-*

.travis.yml

@@ -0,0 +1,35 @@
+# Config file for automatic testing at travis-ci.org
+dist: xenial
+language: python
+sudo: required
+matrix:
+  include:
+    - name: Python 2.7
+      python: 2.7
+      env: python_version=2.7
+
+    - name: Python 3.5
+      python: 3.5
+      env: python_version=3.5
+
+    - name: Python 3.6
+      python: 3.6
+      env: python_version=3.6
+
+    - name: Python 3.7
+      python: 3.7
+      env: python_version=3.7
+
+cache:
+  directories:
+    - eggs
+install:
+  - pip install -U pipenv
+  - pipenv install --dev
+  - sleep 5
+script:
+  - make lint
+  - make clean
+  - pytest -s --cov=smime/ -s --tb=native -v --cov-report term-missing --cov-append smime/
+after_success:
+  - codecov

CHANGES.rst

@@ -0,0 +1,14 @@
+=======
+CHANGES
+=======
+
+0.1.0b2 (unreleased)
+--------------------
+
+- Initial release.
+
+
+0.1.0b1 (2019-01-06)
+--------------------
+
+- Initial release.

MANIFEST.in

@@ -0,0 +1,14 @@
+graft smime
+include AUTHORS
+include CONTRIBUTING.md
+include CHANGES.rst
+include LICENSE
+include README.rst
+
+recursive-exclude test *
+recursive-exclude tool *
+recursive-exclude * __pycache__
+recursive-exclude * *.py[co]
+
+exclude Makefile .editorconfig Pipfile* tox.ini .coveragerc
+

Makefile

@@ -0,0 +1,32 @@
+clean: clean-build clean-pyc clean-test ## remove all build, test, coverage and Python artifacts
+
+clean-build: ## remove build artifacts
+	rm -fr build/
+	rm -fr dist/
+	rm -fr .eggs/
+	find . -name '*.egg-info' -exec rm -fr {} +
+	find . -name '*.egg' -exec rm -f {} +
+
+clean-pyc: ## remove Python file artifacts
+	find . -name '*.pyc' -exec rm -f {} +
+	find . -name '*.pyo' -exec rm -f {} +
+	find . -name '*~' -exec rm -f {} +
+	find . -name '__pycache__' -exec rm -fr {} +
+
+clean-test: ## remove test and coverage artifacts
+	rm -fr .tox/
+	rm -f .coverage
+	rm -fr htmlcov/
+	rm -fr .pytest_cache
+
+lint: ## check style with flake8
+	flake8 smime/
+
+isort: ## run isort recursively
+	isort smime/ -rc
+
+test: ## run tests quickly with the default Python
+	py.test smime/tests
+
+install: clean ## install the package to the active Python's site-packages
+	python setup.py install

Pipfile

@@ -0,0 +1,19 @@
+[[source]]
+name = "pypi"
+url = "https://pypi.org/simple"
+verify_ssl = true
+
+[dev-packages]
+smime = {path = ".",extras = ["test"],editable = true}
+
+[packages]
+cryptography = "*"
+asn1crypto = "*"
+flake8 = "*"
+flake8-isort = "*"
+isort = "*"
+certifi = "*"
+zest-releaser = {extras = ["recommended"],version = "*"}
+
+[requires]
+python_version = "2.7"