DOC: Update supported compiler versions to C++17

This follows changes in the main repository, described in this commit:
InsightSoftwareConsortium/ITK@45407f3

Author: dzenanz

SoftwareGuide/Latex/Introduction/Installation.tex

@@ -33,9 +33,9 @@ \chapter{Configuring and Building ITK}
 %% to ensure that support is maintained.
 %%
 \begin{itemize}
-\item GCC 5.1 and newer
-\item Visual Studio 2017 and 2019, toolsets v141 and v142
-\item Xcode 7.2.1 Apple LLVM Clang version 7.0.2 (clang-700.1.81) and newer
+\item GCC 7 and newer
+\item Visual Studio 2017 version 15.7 and newer
+\item Xcode 10.0 (Apple LLVM Clang version 10.0.0) and newer
 \end{itemize}
 
 If you are currently using an outdated compiler this may be an excellent excuse