Update binding_of_caller
Update binding_of_caller

There is a bug for the old version which affectes some Ruby versions.
Generate Gemfile with our current Ruby version 2.5.0.

openSUSE/osem,differentreality/osem,differentreality/osem,AndrewKvalheim/osem,AndrewKvalheim/osem,differentreality/osem,AndrewKvalheim/osem,rishabhptr/osem,SeaGL/osem,hennevogel/osem,SeaGL/osem,hennevogel/osem,rishabhptr/osem,hennevogel/osem,openSUSE/osem,rishabhptr/osem,rishabhptr/osem,differentreality/osem,openSUSE/osem,SeaGL/osem,hennevogel/osem