Enforces intel icpc >= 2017, fixes #1121 (#1363)

diff --git a/docs/intro.rst b/docs/intro.rst
index 3e9420e..118cb50 100644
--- a/docs/intro.rst
+++ b/docs/intro.rst
@@ -91,4 +91,4 @@
 1. Clang/LLVM (any non-ancient version with C++11 support)
 2. GCC 4.8 or newer
 3. Microsoft Visual Studio 2015 or newer
-4. Intel C++ compiler v15 or newer
+4. Intel C++ compiler v17 or newer (v16 with pybind11 v2.0 and v15 with pybind11 v2.0 and a `workaround <https://github.com/pybind/pybind11/issues/276>`_ )