Support the `brew instal` typo

Because `gem instal` works too.

1 files changed, 1 insertions, 0 deletions

diff --git a/bin/brew b/bin/brew
index e4fa968e5..fd72dce09 100755
--- a/bin/brew
+++ b/bin/brew
@@ -55,6 +55,7 @@ begin
              '-S' => :search,
              'up' => :update,
              'ln' => :link,
+             'instal' => :install, # gem does the same
              'rm' => :uninstall,
              'remove' => :uninstall,
              'configure' => :diy,