KUDO package create isn't reproducible

[nfnt]

What happened:
When creating a package with kubectl kudo create $package the package's digest will differ in different environments while the input is the same.

What you expected to happen:
Package digest should stay the same in different environments for the same package definition.

How to reproduce it (as minimally and precisely as possible):

$ git clone https://github.com/kudobuilder/operators.git operators
$ cd operators
$ kubectl kudo package create repository/first-operator/operator
$ shasum first-operator-0.1.0.tgz
f461370ce5a9f8cac2a50029c8739c4bdb09681a  first-operator-0.1.0.tgz

$ git clone https://github.com/kudobuilder/operators.git operators2
$ cd operators2
$ kubectl kudo package create repository/first-operator/operator
$ shasum first-operator-0.1.0.tgz
15dde373f3209d91302ef0a054e2e6222a64f192  first-operator-0.1.0.tgz

Anything else we need to know?:

Environment:

• Kubernetes version (use kubectl version):
• Kudo version (use kubectl kudo version):
• Operator:
• operatorVersion:
• Cloud provider or hardware configuration:
• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a):
• Install tools:
• Others: