Add configurations to build binary wheels on GNU/Linux and Windows

Thanks to cibuildwheel, now every commit will trigger a build of manylinux1
wheels for Python 3.4, 3.5 and 3.6, both on GNU/Linux (travis-ci.org) and
Windows (ci.appveyor.com). Each build will be followed by a run of the test
suite.

On tags, if everything is ok, the wheel will be eventually automatically
uploaded to PyPI.

This fixes issue #67.

.travis.yml

@@ -1,7 +1,29 @@
 language: python
-python:
-  - "3.4"
-  - "3.5"
-  - "3.6"
-install: "pip install -r requirements-test.txt"
-script: "py.test ./tests"
+python: "3.6"
+
+matrix:
+  include:
+    - sudo: required
+      services:
+        - docker
+#    - os: osx
+#      language: generic
+#      env:
+#        - PY_VERSION=3
+
+env:
+  global:
+    - CIBW_TEST_REQUIRES="pytest pytest-benchmark pytz"
+    - CIBW_TEST_COMMAND="py.test {project}/tests"
+    - CIBW_SKIP="cp2* cp33*"
+    - TWINE_USERNAME=lelit
+      # Note: TWINE_PASSWORD is set in Travis settings
+
+script:
+  - pip install cibuildwheel==0.4.0
+  - cibuildwheel --output-dir wheelhouse
+  - |
+    if [[ $TRAVIS_TAG ]]; then
+      pip install twine
+      twine upload wheelhouse/*.whl
+    fi

appveyor.yml

@@ -0,0 +1,24 @@
+environment:
+  global:
+    CIBW_TEST_REQUIRES: "pytest pytest-benchmark pytz"
+    CIBW_TEST_COMMAND: "py.test {project}/tests"
+    CIBW_SKIP: "cp2* cp33*"
+    TWINE_USERNAME: lelit
+    # Note: TWINE_PASSWORD is set in Appveyor settings
+  matrix:
+    - PYTHON: "C:\\Python35-x64\\python.exe"
+
+install: "git submodule update --init --recursive"
+
+build_script:
+  - "%PYTHON% -m pip install cibuildwheel==0.4.0"
+  - "%PYTHON% -m cibuildwheel --output-dir wheelhouse"
+  - ps: >-
+      if ($env:APPVEYOR_REPO_TAG -eq "true") {
+        %PYTHON% -m pip install twine
+        %PYTHON% -m twine upload (resolve-path wheelhouse\*.whl)
+      }
+
+artifacts:
+  - path: "wheelhouse\\*.whl"
+    name: Wheels