Replace "install" with "installation" where appropriate

Author: grantpalin

README.md

@@ -1,7 +1,7 @@
 wp-cli/find-command
 ===================
 
-Find WordPress installs on the filesystem.
+Find WordPress installations on the filesystem.
 
 [![Build Status](https://travis-ci.org/wp-cli/find-command.svg?branch=master)](https://travis-ci.org/wp-cli/find-command)
 
@@ -14,13 +14,13 @@ wp find <path> [--skip-ignored-paths] [--include_ignored_paths=<paths>] [--max_d
 ~~~
 
 Recursively iterates subdirectories of provided `<path>` to find and
-report WordPress installs. A WordPress install is a wp-includes directory
+report WordPress installations. A WordPress installation is a wp-includes directory
 with a version.php file.
 
 Avoids recursing some known paths (e.g. /node_modules/, hidden sys dirs)
 to significantly improve performance.
 
-Indicates depth at which the WordPress install was found, and its alias,
+Indicates depth at which the WordPress installation was found, and its alias,
 if it has one.
 
 ```