Replace deprecated electron-prebuilt with electron@2.0.18

- Updated package.json to use electron@2.0.18 instead of electron-prebuilt@1.4.3
- Modified lib/jibo-cli.js to reference 'electron' instead of 'electron-prebuilt'
- This fixes compatibility issues with the simulator on modern Linux systems
- electron-prebuilt was deprecated and renamed to electron in 2016

node_modules/electron/dist/LICENSE

@@ -0,0 +1,20 @@
+Copyright (c) 2013-2018 GitHub Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

node_modules/electron/dist/version

@@ -0,0 +1 @@
+v2.0.18