Wrap gitmessage template path in closure

Since the only thing the `repo` argument to `with_repo_or_exit` was used
for, was to extract the gitmessage template path from it, we can just do
that directly instead.

src/bin/git-mob.rs

@@ -1,5 +1,4 @@
-use git_mob::{Author, get_main_author, get_available_coauthors, gitmessage_template_file_path, with_repo_or_exit};
-use git2::Repository;
+use git_mob::{Author, get_main_author, get_available_coauthors, with_gitmessage_template_path_or_exit};
 use structopt::StructOpt;
 use std::process;
 use std::fs;
@@ -37,9 +36,7 @@ fn write_coauthors_to_gitmessage_file(coauthor_initials: &[String]) {
         content.push_str(&format!("Co-authored-by: {}\n", &author.to_string()));
     }
 
-    with_repo_or_exit(|repo: Repository| {
-        let path = gitmessage_template_file_path(repo);
-
+    with_gitmessage_template_path_or_exit(|path| {
         match fs::write(path, content) {
             Ok(_) => {
                 println!("{}", get_main_author());

src/bin/git-solo.rs

@@ -1,13 +1,11 @@
-use git2::Repository;
 use std::fs::File;
-use git_mob::{get_main_author, gitmessage_template_file_path, with_repo_or_exit};
+use git_mob::{get_main_author, with_gitmessage_template_path_or_exit};
 
 fn main() {
     let main_author = get_main_author();
     println!("{}", main_author);
 
-    with_repo_or_exit(|repo: Repository| {
-        let path = gitmessage_template_file_path(repo);
+    with_gitmessage_template_path_or_exit(|path| {
         let _template = File::create(path);
     })
 }

src/lib.rs

@@ -57,13 +57,12 @@ fn parse_coauthors_file() -> Result<BTreeMap<String, Author>, Box<dyn Error>> {
     }
 }
 
-pub fn gitmessage_template_file_path(repo: Repository) -> std::path::PathBuf {
-    repo.path().join(".gitmessage")
-}
-
-pub fn with_repo_or_exit<F: FnOnce(Repository)>(f: F) {
+pub fn with_gitmessage_template_path_or_exit<F: FnOnce(std::path::PathBuf)>(f: F) {
     match Repository::open_from_env() {
-        Ok(repo) => f(repo),
+        Ok(repo) => {
+            let path = repo.path().join(".gitmessage");
+            f(path);
+        },
         Err(_e) => {
             eprintln!("Not in a git repository");
             process::exit(1);