Update requests package, and others

This is primarily to resolve a vulnerability: CVE-2018-18074 [1]
(It's not clear to me that an https-to-http redirect is very feasible,
so this seems like a pretty difficult vulnerability to harness,
but it's probably worth fixing anyway.)

Since it's difficult [2] to upgrade just individual parts of the lockfile,
and since it's not all that important to only upgrade `requests`,
this commit upgrades everything.
In particular, pyyaml is upgraded to 3.13 and jenkins-job-builder
is upgraded from 3e7ad9692655450fe26371770ec87a17e2a0b23a to
1940ed63e06949d4224d64e12afae437d9d0c089.

[1]: psf/requests#4716,
     https://github.com/CruGlobal/jenkins-jobs/network/alert/Pipfile.lock/requests/open

[2]: pypa/pipenv#966
     (Which is way too long of a thread, but the gist is
     pipenv now has a --selective-upgrade option but it doesn't work right)

Pipfile

@@ -11,7 +11,7 @@ name = "pypi"
 
 [packages]
 
-requests = "*"
+requests = ">=2.20.0"
 pyyaml = "*"
 jenkins-job-builder = {ref = "modifications-for-cru-jenkins", git = "https://github.com/CruGlobal/jenkins-job-builder.git", editable = true}