Most recent available pod GradientView version 2.3.3 doesn't compile with xCode 10.2.1

[andrew-nemtsev]

Pod GradientView hasn't source code changes performed at commit "Upgrade for Xcode 10 and Swift 4.2" (e329cea#diff-69db45e24338624ff910c00d92e8546f).
So Swift Compiler Error is produced at GradientView.swift at line 202: "Using '!' is not allowed here; perhaps '?' was intended?"