Check if there are conflicts on master when running the build

- This is taken from
  https://github.com/alphagov/specialist-publisher/commit/9a097249c142c6e7146706dfd5fc0282c92f4886,
  as a thing discussed in tech lead standup that could be useful and
  passed to me to do via Jamie.
Merge pull request #106 from alphagov/jenkins_test_merge_result_of_branches

Check if there are conflicts on master when running the build
Update db/structure.sql

* No changes directly relevant to bouncer
* Has new `host_paths.canonical_path`
Remove path_hash from bouncer tests

* Was required when it was part of a UNIQUE index
* Following deploy of
  https://github.com/alphagov/transition/commit/1b8887ba4f5d9150edb24e6ce6b0fe6a918922d2
  is not required
* No longer need digest/sha1
Merge pull request #107 from alphagov/remove-path-hash-references

Remove path hash references
Tidy up comment referring to hash
Update db/structure.sql to remove path_hash columns

This is dumped from Transition's database in dev, as usual. That dump
also wanted to remove the following line, but I haven't included that
change in this commit:

SET lock_timeout = 0;
Merge pull request #108 from alphagov/update_db_structure_without_path_hash

Update db/structure.sql to remove path_hash columns
Merge pull request #109 from alphagov/remove-path-hash-references

Tidy up comment referring to hash
Stop using pgcrypto extension

We've dropped path_hash so don't need this any more (Bouncer never
relied on it anyway).
Merge pull request #110 from alphagov/pgcrypto-no-no-no

Stop using pgcrypto extension
Add preemptive redirect rules for Ofsted inspection reports

Ofsted has c. 170,000 report pages for various schools and institutions, each with pdfs and other attachments. These will eventually be redeveloped into some sort of a service domain, but are currently excluded from transition as a tool/transaction. These will temporarily be hosted at a subdomain: http://reports.ofsted.gov.uk

This rule prevents the need for the transition tool to contain these 400,000(?) mappings; the site structure is consistent across both namespaces.
Merge pull request #111 from rjc123/new-rules

Add preemptive redirect rules for Ofsted inspection reports