Bazel examples

AppVeyor	Bazel CI

Bazel examples that extend use cases present in the official bazel examples. Some of these examples are explained also in the presentation Introduction to Bazel to build C++ and Python.

List of examples:

• Bazel with third party dependencies
• Basic C++ example
• Basic code coverage computation for C++
• Basic Python example
• Bazel Macros: Generate cpp files using Python
• Explicitly declare autodetected C++ toolchain when compiling on Linux
• Explicitly declare autodetected C++ toolchain when compiling on Windows