add Ubuntu 18 and remove Ubuntu 14
@@ -8,7 +8,7 @@ Recommended Environments
We recommend the following Linux distributions.
-* `Ubuntu <https://www.ubuntu.com/>`_ 14.04 / 16.04 LTS (64-bit)
+* `Ubuntu <https://www.ubuntu.com/>`_ 16.04 / 18.04 LTS (64-bit)
* `CentOS <https://www.centos.org/>`_ 7 (64-bit)
.. note::
@@ -97,7 +97,7 @@ When installing from source, C++ compiler such as ``g++`` is required.
You need to install it before installing CuPy.
This is typical installation method for each platform::
- # Ubuntu 14.04
+ # Ubuntu 16.04
$ apt-get install g++
# CentOS 7
