Also try to install it on AppVeyor

LIB is already an environment variable on Windows

Make all apis use the uint8_t and size_t types

Move clang-tidy into python-based tests

Clean up tests

Modify the tests to no longer construct the classes multiple times and
to have them make use of the new helpers.make() function.

Add formatting tests to the python-based testing framework.

Valgrind in python

Move builds to CircleCI build service

Build on circleci, should be much faster.

Un-align input byte arrays to catch assumptions about data alignment

Greatly simplify container builds

Set windows warnings to W4

Faster check of makefile dependencies