Update readme and changelog

Author: Andreas Frömer

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## [0.8.0] - TBA
+### Changed
+- Dropped support for php7.2
+- Dropped support for `symfony/process:^4.4`
+
 ## [0.7.1] - 2020-05-27
 ### Added
 - Added `Scope` unit ([#32](https://github.com/icanhazstring/systemctl-php/pull/32)) (thanks to [@peter279k](https://github.com/peter279k))

README.md

@@ -9,9 +9,7 @@ $ composer require icanhazstring/systemctl-php
 ```
 
 ## Current supported units
-- service
-- timer
-- socket
+See [Units](src/Unit)
 
 > If you like to add support for more units, feel free to grab an issue and contribute.
 
@@ -57,7 +55,7 @@ $systemCtl->getService('nginx')->stop();
 ```
 
 # How to Contribute
-Simply clone the repo and install using `composer`
+Clone the repo and install using `composer`
 
 ```bash
 $ composer install