Use pessimistic locking on Ruby version in Gemfile
Use pessimistic locking on Ruby version in Gemfile

[#140770891]

Signed-off-by: Sam Smith <03a07629efb0a02c7bbe7cc340a4243da1ab861a@gmail.com>

cloudfoundry/staticfile-buildpack,dhaywael/static-buildpack,cloudfoundry/staticfile-buildpack,cloudfoundry/staticfile-buildpack,dhaywael/static-buildpack,SaberZaabouti/myBuildpack,jockhip12/mybuildpack,SaberZaabouti/myBuildpack,SaberZaabouti/myBuildpack,dhaywael/static-buildpack,jockhip12/mybuildpack,dhaywael/static-buildpack,jockhip12/mybuildpack,dhaywael/static-buildpack,cloudfoundry/staticfile-buildpack,SaberZaabouti/myBuildpack,SaberZaabouti/myBuildpack,jockhip12/mybuildpack,jockhip12/mybuildpack