remove unused files

* remove unused e command
* remove unused gbrt command

bin/e

@@ -1,7 +0,0 @@
-#!/bin/sh
-
-if [ "$1" == "" ]; then
-  exec $EDITOR .
-else
-  exec $EDITOR $1
-fi

bin/gbrt

@@ -1,42 +0,0 @@
-#!/usr/bin/env ruby
-
-def format_commit_info timestamp, time_desc, commit_id, message, ref_name
-  [
-    "#{timestamp.strftime("%y %b %d")}, #{timestamp.strftime("%l:%M%p").downcase}",
-    "(#{time_desc})",
-    commit_id,
-    message,
-    ref_name
-  ]
-end
-
-def render_commit_info timestamp, time_desc, commit_id, message, ref_name, merged
-  [
-    timestamp,
-    time_desc,
-    "\e[32m#{ref_name}\e[0m",
-    (merged ? "  #{commit_id}" : "+ \e[33m#{commit_id}\e[0m"),
-    "\e[#{message[/^Temp/] ? 31 : 90}m#{message.strip}\e[0m"
-  ].join(' ')
-end
-
-commit_info = `git branch #{ARGV.join(' ')} | cut -c 3-`.strip.split("\n").reject {|ref_name|
-  ref_name[' -> ']
-}.map {|ref_name|
-  `git log --no-walk --pretty=format:"%ct\n%cr\n%h\n%s" '#{ref_name}' --`.strip.split("\n").push(ref_name)
-}.map {|commit_info|
-  [Time.at(commit_info.shift.to_i)].concat(commit_info)
-}.sort_by {|commit_info|
-  commit_info.first # unix timestamp
-}.reverse.map {|commit_info|
-  format_commit_info(*commit_info)
-}.transpose.map {|column|
-  max_col_length = column.sort_by {|i| i.length }.last.length
-  column.map {|i| i.ljust(max_col_length) }
-}.transpose.map {|commit_info|
-  commit_info.push(
-    `git merge-base HEAD #{commit_info[2]}`.chomp[0...7] == commit_info[2]
-  )
-}.each {|commit_info|
-  puts render_commit_info(*commit_info)
-}