fixup! Bump minimum CMake version to 3.11

Author: ajaust

README.md

@@ -97,7 +97,7 @@ A copy of segyio is available both as pre-built binaries and source code:
 To build segyio you need:
  * A C99 compatible C compiler (tested mostly on gcc and clang)
  * A C++ compiler for the Python extension, and C++11 for the tests
- * [CMake](https://cmake.org/) version 2.8.12 or greater
+ * [CMake](https://cmake.org/) version 3.11 or greater
  * [Python](https://www.python.org/) 3.9 or greater
  * [numpy](http://www.numpy.org/) version 1.10 or greater
  * [setuptools](https://pypi.python.org/pypi/setuptools) version 28 or greater