Fix Sample app builds by using Xcode10.2

[alexch2000]

PR update needle to 10.2 to prevent the needle app crash on the sample build app. This happens because Xcode10.1 image doesn't have swift runtime which is required by app

This includes:

• use xcode10.2 image to Travis builds
• update deployment target to 12.2
• remove static-stdlib generation since Swift compiler no longer supports statically linking the Swift libraries. They're included in the OS by default starting with macOS Mojave 10.14.4.

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[alexch2000]

@rudro, @sbarow can you review this? It will fix builds