Remove `--force` option for installing bundler because Ruby 2.5.0 does not have bundler by default.
Remove `--force` option for installing bundler
because Ruby 2.5.0 does not have bundler by default.

cdinger/oracle-enhanced,yahonda/oracle-enhanced,yahonda/oracle-enhanced,cdinger/oracle-enhanced,rshell/oracle-enhanced,rshell/oracle-enhanced,rsim/oracle-enhanced,rsim/oracle-enhanced