travis: build without SSL and ZMQ packages as well

[ogasser]

Explicitly build without libssl-dev and libczmq-dev.

[ogasser]

The build check should fail for this PR, but it does not. It seems that libssl-dev is installed by default in travis.

@bluca @nickbroon @evintila Does anyone of you know a way to blacklist/uninstall apt packages in travis (without sudo)?

[nickbroon]

I've pushed a commit to #87 that IO think addresses this. Test build happening here: https://travis-ci.org/nickbroon/vermont/builds/315899580 I expect 42.1 to fail.

[ogasser]

@nickbroon Unfortunately travis seems to include openssl by default. I cherry picked your commit de78ab3 on top of master, which should fail the build but it does not. See here: https://travis-ci.org/tumi8/vermont/jobs/315899546#L1

[nickbroon]

My test job https://travis-ci.org/nickbroon/vermont/jobs/315899581 did not fail, so it does appear that libssl-dev is part of the base Travis Trusty Ubuntu container. hmm.....

[ogasser]

Yep, exactly. Is there a way to uninstall packages in travis?

[nickbroon]

In a container it's also not possible to use something like `sudo apt-get remove libssl-dev' as sudo is not allowed. Nor is there an obvious reason why default install has libssl-dev in the first place. I'll investigate what other options are available.

87 should still be good to merge at the moment, to address the immediate build issue.

[ogasser]

Yes. Can we have different build environment for each job? I.e. VM env for building without SSL and container env for building with SSL.

[bluca]

you can add sudo: required/false as any other flag (compiler, os, etc)

[ogasser]

@bluca great! @nickbroon Can you add that to PR #87?

[nickbroon]

I'm testing just now: https://travis-ci.org/nickbroon/vermont/builds/315914107

[nickbroon]

I've updated #87 with a change to remove the libssl-dev package making use on VM instead of container.

[ogasser]

Thanks @bluca & @nickbroon !