Update module gorilla/handlers to v1.5.1

See merge request !13

Update module contrib.go.opencensus.io/exporter/zipkin to v0.1.2

See merge request !10

Update module go.opencensus.io to v0.22.5

See merge request !11

This reverts commit f8bba073.

That version is incompatible with go 1.11 (debian).

Update golang.org/x/crypto commit hash to eec23a3

See merge request !6

Update golang.org/x/sync commit hash to 09787c9

See merge request !7

Update github.com/emersion/go-textwrapper commit hash to 65d8968

See merge request !4

Update github.com/lunixbochs/struc commit hash to 784aaeb

See merge request !5

Configure Renovate

See merge request !3

Refactor the pwhash package to split the various encoders into their
own files for readability.

Useful for large blob responses.

Run tests via Gitlab CI

See merge request !2

This is a high-level timeout for the http.Handler application code,
not a low-level network timeout.

Add the 'connect_timeout' and 'request_max_timeout' configuration
fields, to control respectively the initial connection timeout, and
the maximum time for each individual request. This allows fine-tuning
of the expected performance of specific backends, for example to let
optional backends fail fast.

We're using language-specific Markdown templates to allow simultaneous
generation of text and HTML for fancy multipart/alternative
emails. The package also supports PGP/MIME for signatures (no
encryption yet).