Add rule for pip_install permission fix (#895)

* Add rule for pip_install permission fix

* Fix whitespace

* Switch quotation to single

* remove 2nd else

* E261 indent comment

README.md

@@ -266,6 +266,7 @@ following rules are enabled by default:
 * `no_command` – fixes wrong console commands, for example `vom/vim`;
 * `no_such_file` – creates missing directories with `mv` and `cp` commands;
 * `open` – either prepends `http://` to address passed to `open` or create a new file or directory and passes it to `open`;
+* `pip_install` – fixes permission issues with `pip install` commands by adding `--user` or prepending `sudo` if necessary;
 * `pip_unknown_command` – fixes wrong `pip` commands, for example `pip instatl/pip install`;
 * `php_s` – replaces `-s` by `-S` when trying to run a local php server;
 * `port_already_in_use` – kills process that bound port;