Bump govuk_tech_docs from 1.8.0 to 1.8.2 (#52)

Bumps [govuk_tech_docs](https://github.com/alphagov/tech-docs-gem) from 1.8.0 to 1.8.2.
- [Release notes](https://github.com/alphagov/tech-docs-gem/releases)
- [Changelog](https://github.com/alphagov/tech-docs-gem/blob/master/CHANGELOG.md)
- [Commits](https://github.com/alphagov/tech-docs-gem/commits)

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -1,7 +1,7 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (5.0.7.1)
+    activesupport (5.0.7.2)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
@@ -10,15 +10,15 @@ GEM
       public_suffix (>= 2.0.2, < 4.0)
     autoprefixer-rails (6.7.7.2)
       execjs
-    backports (3.12.0)
+    backports (3.14.0)
     chronic (0.10.2)
     chunky_png (1.3.11)
     coderay (1.1.2)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    commonmarker (0.18.2)
+    commonmarker (0.20.0)
       ruby-enum (~> 0.5)
     compass (1.0.3)
       chunky_png (~> 1.2)
@@ -34,7 +34,7 @@ GEM
       sass (>= 3.2, < 3.5)
     concurrent-ruby (1.1.5)
     contracts (0.13.0)
-    dotenv (2.7.1)
+    dotenv (2.7.2)
     em-websocket (0.5.1)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
@@ -44,7 +44,7 @@ GEM
     fast_blank (1.0.0)
     fastimage (2.1.5)
     ffi (1.10.0)
-    govuk_tech_docs (1.8.0)
+    govuk_tech_docs (1.8.2)
       activesupport
       chronic (~> 0.10.2)
       middleman (~> 4.0)
@@ -137,12 +137,12 @@ GEM
       tilt (>= 1.4.1, < 3)
     padrino-support (0.13.3.4)
       activesupport (>= 3.1)
-    parallel (1.14.0)
+    parallel (1.17.0)
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (3.0.3)
-    rack (2.0.6)
+    rack (2.0.7)
     rack-livereload (0.3.17)
       rack
     rake (12.3.2)