* internal/initwd: fix panics with relative submodules in DirFromModule
There were two related issues here:
1. panic with any local module with submodules
1. panic with a relative directory that was above the workdir ("../")
The first panic was caused by the local installer looking up the root
module with the (nonexistant) key "root.", instead of "".
The second panic was caused by the installer trying to determine the
relative path from ".". This was fixed by detecting "." as the source
path and using the absolute path for the call to filepath.Rel.
Added test cases for both panics and updated the existing e2e tests with
the correct install paths.
faster
The acceptance tests for etcdv3, oss and manta were not validating
required env variablea, chosing to assume that if one was running
acceptance tests they had already configured the credentials.
It was not always clear if this was a bug in the tests or the provider,
so I opted to make the tests fail faster when required attributes were
unset (or "").
Identify module sources that look like relative paths ("child" instead
of "./child", for example) and surface a helpful error.
Previously, such module sources would be passed to go-getter, which
would fail because it was expecting an absolute, or properly relative,
path. This commit moves the check for improper relative paths sooner so
a user-friendly error can be displayed.