remove unused file

frontend/src/metabase/xray/SimpleHistogram.jsx

-import React from 'react'
-import cx from 'classnames'
-
-const SimpleHistogram = ({ data, height = 120, gridLines = true, legends = true , showValues = true}) => {
-
-    const max = Math.max.apply(null, Object.values(data))
-
-    const getHeight = (val) => {
-        return val / max * 100
-    }
-
-    return (
-        <div>
-            <ol
-                className="flex full"
-                style={{
-                    height,
-                    backgroundImage: gridLines ? `linear-gradient(to top,
-                        rgba(0, 0, 0, 0.1) 2%,
-                        rgba(0, 0, 0, 0) 2%)` : null,
-                    backgroundSize: `100% ${height/4}px`,
-                    backgroundPosition: 'left top',
-                }}
-            >
-                { data && Object.keys(data).map(key =>
-                    <li
-                        key={key}
-                        className="relative flex-full bg-brand"
-                        style={{
-                            marginTop: 'auto',
-                            border: '0.25px solid #fff',
-                            height: `${getHeight(data[key])}%`,
-                            opacity: 0.85
-                        }}
-                    >
-                        <span
-                            className={cx('absolute left text-bold right text-centered', { 'hidden': !showValues })}
-                            style={{ top: -20 }}
-                        >
-                            {data[key]}
-                        </span>
-                    </li>
-                )}
-            </ol>
-            { legends && (
-                <ol
-                    className="flex full my2"
-                >
-                    { data && Object.keys(data).map(key =>
-                        <li
-                            key={key}
-                            className="flex-full text-bold text-centered"
-                        >
-                            {key}
-                        </li>
-                    )}
-                </ol>
-            )}
-        </div>
-    )
-}
-
-export default SimpleHistogram