Update minimum version of compilers/platforms

INSTALL.md

@@ -18,9 +18,9 @@
 You should be able to compile Aseprite successfully on the following
 platforms:
 
-* Windows 10 + [Visual Studio Community 2019 + Windows 10.0.17763.0 SDK](https://imgur.com/4Pq2Cbv)
-* macOS 10.14.4 Mojave + Xcode 10.2.1 + macOS 10.14 SDK
-* Linux + gcc 4.8 or clang 7.0
+* Windows 10 + [Visual Studio Community 2019 + Windows 10.0.18362.0 SDK](https://imgur.com/a/7zs51IT)
+* macOS 10.15.3 Mojave + Xcode 11.2.1 + macOS 10.15 SDK (older version might work)
+* Linux + gcc 9.2 or clang 9.0
 
 # Get the source code
 
@@ -60,7 +60,7 @@ To compile Aseprite you will need:
 
 * Windows 10 (**we don't support cross-compiling and don't know if this would be possible**)
 * [Visual Studio Community 2019](https://visualstudio.microsoft.com/downloads/)
-* The [Desktop development with C++ item + Windows 10.0.17763.0 SDK](https://imgur.com/4Pq2Cbv)
+* The [Desktop development with C++ item + Windows 10.0.18362.0 SDK](https://imgur.com/a/7zs51IT)
   from the Visual Studio installer
 
 ## macOS dependencies