jitpack.io failed to resolve github repo

For anyone else that made the simple mistake I made:

Ensure you add the maven { url "https://jitpack.io" } under allprojects instead of buildscript.

Project build.gradle file:

buildscript {
    repositories {
        jcenter()
        // DO NOT ADD IT HERE!!!
    }
    ...
}

allprojects {
    repositories {
        mavenLocal()
        jcenter()
        // ADD IT HERE
        maven { url "https://jitpack.io" }
    }
}

Thanks to Alexander Pacha for pointing that out in a comment above.