Please support CLion

[jayessdeesea]

I see the following error when trying to manually install in CLion-2020.2:

7:10 PM Plugin Error: Plugin "Amazon Ion IntelliJ IDEA Plugin" is incompatible (supported only in IntelliJ IDEA).

[belloale]

We can target this after this has been merged #17

This will require changing the gradle build a bit more so that we can support the lack of Java plugin APIs in CLion. Also the plugin.xml file needs to be a bit different for CLion.

Docs are here: https://plugins.jetbrains.com/docs/intellij/clion.html#available-clion-apis