Add a run package responsible for running git commands

- Add better git error handling
- Move repo helpers into a separate package

pkg/git/config.go

@@ -1,20 +1,19 @@
 package git
 
-import "os/exec"
+import (
+	"git-get/pkg/run"
+)
 
 // ConfigGlobal represents a global gitconfig file.
 type ConfigGlobal struct{}
 
 // Get reads a value from global gitconfig file. Returns empty string when key is missing.
 func (c *ConfigGlobal) Get(key string) string {
-	cmd := exec.Command("git", "config", "--global", key)
-	out, err := cmd.Output()
-
+	out, err := run.Git("config", "--global").AndCaptureLine()
 	// In case of error return an empty string, the missing value will fall back to a default.
 	if err != nil {
 		return ""
 	}
 
-	lines := lines(out)
-	return lines[0]
+	return out
 }