set the required standard to C++14

Summary:
To avoid compilation errors such as

  error: no template named 'enable_if_t' in namespace 'std'; did you mean 'enable_if'?

Reviewed By: tschrager

Differential Revision: D8757706

fbshipit-source-id: 96dc359fa88f5059be972afb5b7c3e1a00701842

surround360_render/CMakeLists.txt

@@ -1,6 +1,7 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 3.2)
 
 PROJECT(Surround360Render CXX)
+set(CMAKE_CXX_STANDARD 14)
 
 FIND_PACKAGE(OpenCV)
 FIND_PACKAGE(Ceres REQUIRED)