Update license to Eclipse Public License 2.0 (EPL-2.0)?

[amotl]

Dear @jpmens,

while working on #127, we (almost) bumped the license used by mqttwarn to the Eclipse Public License version 2.0.

To make this happen, we also voted for inclusion of this license into the list of Trove classifiers for PyPI, see also pypi/warehouse#3660.

May we humbly ask you if you actually approve that?

Thanks,
Andreas.

[jpmens]

I'm accepting this proposal, because the FSF states:

In terms of GPL compatibility, the Eclipse Public License version 2.0 is essentially equivalent to version 1.0. The only change is that it explicitly offers the option of designating the GNU GPL version 2 or later as a "secondary license" for a certain piece of code.

[amotl]

Thanks for doing further investigations about this topic, @jpmens! And good to hear about the outcome.