Merge changes from edina/CuriousEdinburgh2

Updated the app to support latest React Native version (version 0.59.9)
at time of writing.

- updated all dependencies and devDependencies
- updated the iOS and Android project files so they contained the same
  files and file contents as a virgin React Native 0.59.9 project
- updated app to build 64 bit binaries for Android

Fixed bugs:

- App now scales on iPhone X, Xr, Xs properly
- Sharing a stop now shares the stop url 
- Video player now uses WebView on Android
- Splash Screen on Android now has the correct aspect ratio

Update targetSdkVersion to 26 as this is the minimum allowed for the 
Play store now.

Updated build.gradle to force subprojects to use compileSdkVersion 29
and buildToolsVersion 29.0.0.

Added London as a simulated location for testing iOS

Using WebView for playing video on Android causes the video to simply
play as in the thumbnail rather than full screen (like iOS. 

Previously this was worked around by creating an image thumbnail for the
video, overlaying another image with a play button on it and then 
playing the video in the image modal. This was broken because it was 
embedding an <Image> element within another <Image> element. 

By replacing the outer <Image> element with a <ImageBackground> element
we can work around this.

The pan to my location button doesn’t work in iOS (and Android??) after
the work carried out to