docs: Update version numbers from 4.0.0 -> 4.1.0

docs: Update version numbers from 3.5.0 -> 4.0.0

Merge pull request watson-developer-cloud#395 from watson-developer-c…

…loud/major-pre-release

Major pre release

docs: Update version numbers from 3.4.1 -> 3.5.0

docs: Update version numbers from 3.4.0 -> 3.4.1

docs: Update version numbers from 3.3.0 -> 3.4.0

docs: Update version numbers from 3.2.0 -> 3.3.0

docs: Update version numbers from 3.1.0 -> 3.2.0

docs: Update version numbers from 3.0.0 -> 3.1.0

[skip ci] docs: Update version numbers from 2.16.0 -> 3.0.0