Upgrade OpenSSL to next minor version 1.1.0j

[sukeerthiadiga]

• OpenSSL 1.1.0e -> 1.1.0j
• Change travis-ci config file to pick specific version of bundler.
• Added 2.4, 2.5 and 2.6 ruby versions for testing.

[sukeerthiadiga]

@metaskills by any chance can we merge this.
Credits to @nzdjb. I have pulled his code to fix the build.

[aharpervc]

If you're going to spend the time to reconfigure the build matrix as a prereq for upgrading openssl, I think we should take that opportunity to drop testing for 2.1 (EOL'd 2017-03-31) and 2.2 (EOL'd 2018-03-31). Even 2.3 EOL's 2019-03-31, but I guess we can keep it for now. And then we should probably ensure that 2.4 and 2.5 are tested, and ideally 2.6 as well.

[sukeerthiadiga]

If you're going to spend the time to reconfigure the build matrix as a prereq for upgrading openssl, I think we should take that opportunity to drop testing for 2.1 (EOL'd 2017-03-31) and 2.2 (EOL'd 2018-03-31). Even 2.3 EOL's 2019-03-31, but I guess we can keep it for now. And then we should probably ensure that 2.4 and 2.5 are tested, and ideally 2.6 as well.

This totally makes sense to me. I have added latest 2.4.x, 2.5.x and 2.6.x ruby versions. We should be good now.

[wpolicarpo]

I agree we should drop ruby 2.1 and 2.2 from the matrix. In the end, updating the rvm matrix values was enough.

[nzdjb]

I'm going to close out PR#424 in favour of this.