migrate AdjustStackSpec from spek to kotest

[robstoll]

Platform (all, jvm, js): all
Extension (none, kotlin 1.3): none

Code related feature

We want to move away from spek as it's future regarding maintenance and development is quite unsure.
As I don't want to loose hierarchical test setup I decided that we go with kotest

Following the things you need to do:

• add dependency for the js paltform to kotest in misc/atrium-specs/build.gradle.kts (if not there yet)
• rewrite atrium-core/src/jvmTest/kotlin/ch/tutteli/atrium/reporting/erroradjusters/AdjustStackSpec.kt to kotest extending a DescribeSpec

Your first contribution?

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[maxslimb]

Hey, I'll work on this

[robstoll]

@Dark-Knight11 as you implemented this issue, you can leave a message here if you want, this way I am able to assign it to you

[Dark-Knight11]

Sure

[Dark-Knight11]

Refer to #1233 for this issue