Incorrect versionadded for helix_analysis?

[IAlibay]

The helix_analysis docstring says that it was added in version 1.0.0

mdanalysis/package/MDAnalysis/analysis/helix_analysis.py

Line 32 in 2c714fc

.. versionadded:: 1.0.0

However, it's not (unless I'm missing something) in 1.1.1 (or at least current master).

[IAlibay]

If this is indeed 2.0.0, then we need to add it to the list of #3261 things that need to be dealt with before we release 2.0.0 (so that we don't have to deprecate later).

[orbeckst]

Seems to be a mistake, it never made it into 1.x. We only state that helanal is will be gone and helix_analysis will be in 2.0.0.