Release 0.6.3 - Template through Unix Pipe (#336)

[chfw]

• ✨ support template string from shell pipe. resolves jinja-cli parity: support command line pipe stream #260

• 🔬 test shell pipe feature. test jinja-cli parity: support command line pipe stream #260

• 📚 update documentation

• 🔨 code refactoring

• 💚 fix python 2 compactibility

• 💚 update unit tests

• 🔥 skip windows tests

• ✨ enable tests on python 2 version for additional versions

• 🔥 test if the new test function broke azure build

• 🔥 remove win32 support as it has no pipe

• 👕 coding style update

• 🔥 skip the stdin test on windows

• 💚 better mocking to fix azure macos test, which seems eating console output

• 💚 update one more test case, which seems eating console output

• 💚 update one more test case, which seems eating console output

• 💚 update one more test case, which seems eating console output

• 👕 update change log and version number

Before raising the PR, here is a check list:

• have you written unit tests for your code changes?
• have you updated the change log?
• can someone else understand your changes without your explanation?
• are you proud of your code changes?
• please add your name and github link to contributors.rst in alphabetical order.