* Remove unused Vagrant scripts

* Change package Architecture to any

* Preinstall the wheel package when building venvs.

Addresses the following warnings during Debian builds:

    Using legacy 'setup.py install' for jaeger-client, since package 'wheel' is not installed.
    Using legacy 'setup.py install' for matrix-synapse-ldap3, since package 'wheel' is not installed.
    Using legacy 'setup.py install' for opentracing, since package 'wheel' is not installed.
    Using legacy 'setup.py install' for psycopg2, since package 'wheel' is not installed.
    Using legacy 'setup.py install' for systemd-python, since package 'wheel' is not installed.
    Using legacy 'setup.py install' for pympler, since package 'wheel' is not installed.
    Using legacy 'setup.py install' for threadloop, since package 'wheel' is not installed.
    Using legacy 'setup.py install' for thrift, since package 'wheel' is not installed.

* Allow /etc/default/matrix-synapse to be missing

Per the systemd.exec manpage, prefixing an EnvironmentFile with "-":

> indicates that if the file does not exist, it will not be read and no
> error or warning message is logged.

Signed-off-by: Dan Callahan <danc@element.io>