update py2 notices (#1523)

installation.rst

@@ -17,7 +17,8 @@ There are three ways to install Conan:
 Install with pip (recommended)
 ------------------------------
 
-To install Conan using ``pip``, you need Python 2.7 or >= 3.5 distribution installed on your machine. Python 3.4 support has been dropped. Modern Python distros come
+To install Conan using ``pip``, you need Python >= 3.5 distribution installed on your machine. Python 3.4 support has been dropped and
+:ref:`Python 2<python2>` is being deprecated. Modern Python distros come
 with pip pre-installed. However, if necessary you can install pip by following the instructions in `pip docs`_.
 
 .. warning::
@@ -27,8 +28,8 @@ with pip pre-installed. However, if necessary you can install pip by following t
 
 .. warning::
 
-    Python 2 will soon be deprecated by the Python maintainers. It is strongly recommended to use Python 3 with Conan, especially if need to manage non-ascii filenames or file contents.
-    Conan still supports Python 2, however some of the dependencies have started to be supported only by Python 3. See :ref:`python2` for details.
+    **Python 2 has been deprecated on January 1st, 2020 by the Python maintainers** and Conan project will completely stop working with it
+    in the following releases. See :ref:`python2` for details.
 
 Install Conan:
 
@@ -133,7 +134,7 @@ The response should be similar to:
 Install from source
 -------------------
 
-You can run Conan directly from source code. First, you need to install Python 2.7 or Python 3 and
+You can run Conan directly from source code. First, you need to install Python and
 pip.
 
 Clone (or download and unzip) the git repository and install its requirements:
@@ -194,7 +195,9 @@ All features of Conan until version 1.6 are fully supported in both Python 2 and
 that are only available in Python 3 or more easily available in Python 3 will be implemented and tested only in Python 3, and versions of
 Conan using Python 2 will not have access to that feature. This will be clearly described in code and documentation.
 
-If and when Conan 2.x is released, the level of compatibility with Python 2 may be reduced further.
+Starting in Conan 1.22, Python 2 is no longer supported and Conan will stop working with it in the following releases.
+
+Conan 2.x won't support Python 2.
 
 We encourage you to upgrade to Python 3 as soon as possible. However, if this is impossible for you or your team, we would like to know it.
 Please give feedback in the `Conan issue tracker`_ or write us to info@conan.io.