adjusted README

Author: madduci

README.md

@@ -2,13 +2,13 @@
 
 [![Build Status](https://travis-ci.org/madduci/docker-linux-cpp.svg?branch=master)](https://travis-ci.org/madduci/docker-linux-cpp)
 
-A basic docker image for C++ developers, featuring g++ (from 4.9 up to 7.x) and clang++ (from 3.8 to 6.0) and CMake support. The default compiler is g++ 7, but you're free to modify the Dockerfile and set your own; as example, if you want to set g++ 4.9 as the default compiler, just write the following Dockerfile and build a new image:
+A basic docker image for C++ developers, featuring g++ (from 4.9 up to 8.x) and clang++ (from 3.8 to 6.0) and CMake support. The default compiler is g++ 8, but you're free to modify the Dockerfile and set your own; as example, if you want to set g++ 4.9 as the default compiler, just write the following Dockerfile and build a new image:
 
 ```
 # Dockerfile
 FROM madduci/docker-linux-cpp:latest
 
-RUN update-alternatives --remove g++ /usr/bin/g++-7 \
+RUN update-alternatives --remove g++ /usr/bin/g++-8 \
     && update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.9 1
 ```
 
@@ -30,4 +30,4 @@ You can just type in your terminal:
 
 to use my docker image or, in case of adjustments to the `Dockerfile`, just type:
 
-`docker run --rm -it -v /your/folder:/project madduci/docker-linux-cpp my_file.cpp` 
+`docker run --rm -it -v /your/folder:/project madduci/docker-linux-cpp my_file.cpp`