Don't override view's alpha when using zoom out

[tbaranes]

Close #545

[IBAnimatableBot]

SwiftLint found issues

Warnings

File	Line	Reason
Animatable.swift	634	Function parameters should be aligned vertically if they're in multiple lines in a method call.
Animatable.swift	667	Function parameters should be aligned vertically if they're in multiple lines in a method call.
Animatable.swift	688	Function parameters should be aligned vertically if they're in multiple lines in a method call.
Animatable.swift	153	Functions and methods parameters should be either on the same line, or one per line.
Animatable.swift	166	Functions and methods parameters should be either on the same line, or one per line.
Animatable.swift	178	Functions and methods parameters should be either on the same line, or one per line.
Animatable.swift	239	Functions and methods parameters should be either on the same line, or one per line.
Animatable.swift	267	Functions and methods parameters should be either on the same line, or one per line.
Animatable.swift	514	Functions and methods parameters should be either on the same line, or one per line.
Animatable.swift	534	Functions and methods parameters should be either on the same line, or one per line.
Animatable.swift	556	Functions and methods parameters should be either on the same line, or one per line.

Generated by 🚫 Danger

[JakeLin]

👍 thanks @tbaranes