* switched to poetry for installing project-wide dev dependencies (so we have versions locked)

* fixed appveyor and switched to dev version of PyInstaller

* updated submodules

* updated pyinstaller to use develop branch

* fixed CI on Windows and macOS where virtualenvs aren't set up

* updated appveyor config to install poetry *after* updating pip

* set up virtualenv on macOS and Windows builds

* updated submodule

* fixed virtualenv activation on Windows (travis)

* switched appveyor to 64bit Python and changed all python3 -> python, updated submodule with 64bit pyhook fix

* updated submodules

* added windows to allowed failures temporarily until timeout bug is fixed