feat: prepare and cleanup release event hooks (#349)

Resolves #295
Resolves #330
Resolves #329 (Supports templating of only `releases[].hooks[].command` and `args` right now
Resolves #324

helmexec/runner.go

@@ -15,10 +15,13 @@ type Runner interface {
 }
 
 // ShellRunner implemention for shell commands
-type ShellRunner struct{}
+type ShellRunner struct {
+	Dir string
+}
 
 // Execute a shell command
 func (shell ShellRunner) Execute(cmd string, args []string) ([]byte, error) {
 	preparedCmd := exec.Command(cmd, args...)
+	preparedCmd.Dir = shell.Dir
 	return preparedCmd.CombinedOutput()
 }