v0.8.55

ApproxFunBase v0.8.55

Diff since v0.8.54

Merged pull requests:

• Move DualNumbers to an extension (#565) (@jishnub)
• Move Statistics to an extension (#566) (@jishnub)
• Revert "Move Statistics to an extension" (#567) (@jishnub)
• Revert "Move DualNumbers to an extension" (#568) (@jishnub)
• Revert "Move SpecialFunctions to an extension" (#569) (@jishnub)
• Fix maximum(abs, ::Fun) (#570) (@jishnub)
• Backport: Fix maximum(abs, ::Fun) (#571) (@jishnub)