Upgrade oh-my-zsh (fix #215)

README.md

@@ -65,7 +65,6 @@ Just run `topgrade`. It will run the following steps:
 * Check if the following paths are tracked by Git. If so, pull them:
   * ~/.emacs.d (Should work whether you use [Spacemacs](http://spacemacs.org/) or a custom configuration)
   * ~/.zshrc
-  * [~/.oh-my-zsh](https://github.com/robbyrussell/oh-my-zsh)
   * ~/.tmux
   * ~/.config/fish
   * ~/.config/nvim
@@ -76,6 +75,7 @@ Just run `topgrade`. It will run the following steps:
   * Powershell Profile
   * Custom defined paths
 * **Unix**: Run [zplug](https://github.com/zplug/zplug) update
+* **Unix**: Run [oh-my-zsh](https://github.com/robbyrussell/oh-my-zsh) update
 * **Unix**: Run [fisher](https://github.com/jorgebucaran/fisher)
 * **Unix**: Upgrade tmux plugins with [TPM](https://github.com/tmux-plugins/tpm). *Note*: Do not use
   the `-b` flag in your configuration as suggested by the TPM readme.

src/main.rs

@@ -224,7 +224,6 @@ fn run() -> Result<(), Error> {
     #[cfg(unix)]
     {
         git_repos.insert(base_dirs.home_dir().join(".zshrc"));
-        git_repos.insert(base_dirs.home_dir().join(".oh-my-zsh"));
         git_repos.insert(base_dirs.home_dir().join(".tmux"));
         git_repos.insert(base_dirs.home_dir().join(".config/fish"));
         git_repos.insert(base_dirs.config_dir().join("openbox"));
@@ -267,6 +266,12 @@ fn run() -> Result<(), Error> {
             || unix::run_zplug(&base_dirs, run_type),
             config.no_retry(),
         )?;
+        execute(
+            &mut report,
+            "oh-my-zsh",
+            || unix::run_oh_my_zsh(run_type),
+            config.no_retry(),
+        )?;
         execute(
             &mut report,
             "fisher",

src/steps/os/unix.rs

@@ -26,6 +26,14 @@ pub fn run_zplug(base_dirs: &BaseDirs, run_type: RunType) -> Result<(), Error> {
     run_type.execute(zsh).args(&["-c", cmd.as_str()]).check_run()
 }
 
+pub fn run_oh_my_zsh(run_type: RunType) -> Result<(), Error> {
+    let upgrade = require("upgrade_oh_my_zsh")?;
+
+    print_separator("oh-my-zsh");
+
+    run_type.execute(upgrade).check_run()
+}
+
 pub fn run_fisher(base_dirs: &BaseDirs, run_type: RunType) -> Result<(), Error> {
     let fish = require("fish")?;
     base_dirs