Fix
* Ignore TIFF ``XResolution`` or ``YResolution`` with 0 in the denominator. ([753](https://github.com/imageio/imageio/issues/753)) ([`6b44a1b`](https://github.com/imageio/imageio/commit/6b44a1beb6db73eb53372debf99bb2e24450546f))
Other
* Add section on freezing ([759](https://github.com/imageio/imageio/issues/759)) ([`7699e32`](https://github.com/imageio/imageio/commit/7699e32cee4f48bebdd8ace6a24c05b03ce75eec))
* Update "python_requires" to 3.7+ ([757](https://github.com/imageio/imageio/issues/757)) ([`f80f068`](https://github.com/imageio/imageio/commit/f80f068329123fc3c164c522391969ac8eeb0dd4))