Adds Azure Blob Storage logging endpoint support

[mccurdyc]

Relevant (Referenced) Link(s)

• Fastly API Docs
• fastly/go-fastly

Validation

$ make test

git clone git@github.com:mccurdyc/cli.git /tmp/cli && \
(
    cd /tmp/cli && \
    git checkout mccurdyc/logging-azure && \
    make test && \
    rm -rf /tmp/cli \
)

[mccurdyc]

@phamann I assumed that we wanted to follow the naming convention (i.e., "blobstorage") in go-fastly.

I would personally prefer something that identifies this as an "Azure Blob Storage" rather than just "blob storage" as I think "blob storage" has weighted meaning. But having consistency is also very important.

[mccurdyc]

Force-pushed addressing review comments (i.e., blobstorage -> azureblob) and squashing into a single commit.

1. fd --exclude .git . -exec rename s/blobstorage/azureblob/ {} \;
2. rename blobstorage azureblob pkg/logging/blobstorage*
3. rename blobstorage azureblob pkg/logging/azureblob/*

[mccurdyc]

Force-pushed gofmt check fix.

[phamann]

👍 LGTM

[mccurdyc]

Force-pushed rebasing master.

[mccurdyc]

I didn't realize this was formatted this way when it got merged to master.