remove is-image-url dev dep since it isnt backwards compatible

examples/images/index.js

@@ -3,7 +3,8 @@ import { Editor, Mark, Raw } from '../..'
 import React from 'react'
 import ReactDOM from 'react-dom'
 import initialState from './state.json'
-import isImage from 'is-image-url'
+import isImage from 'is-image'
+import isUrl from 'is-url'
 import { Map } from 'immutable'
 
 /**
@@ -137,6 +138,7 @@ class Images extends React.Component {
 
   onPaste = (e, paste, state) => {
     if (paste.type != 'text') return
+    if (!isUrl(paste.text)) return
     if (!isImage(paste.text)) return
     return this.insertImage(state, paste.text)
   }

package.json

@@ -14,7 +14,6 @@
     "detect-browser": "^1.3.3",
     "esrever": "^0.2.0",
     "immutable": "^3.8.1",
-    "is-image-url": "^1.1.8",
     "keycode": "^2.1.2",
     "lodash": "^4.13.1",
     "react-portal": "^2.2.0",
@@ -42,6 +41,7 @@
     "exorcist": "^0.4.0",
     "gh-pages": "^0.11.0",
     "http-server": "^0.9.0",
+    "is-image": "^1.0.1",
     "is-url": "^1.2.2",
     "mocha": "^2.5.3",
     "prismjs": "^1.5.1",