Build(deps-dev): bump curb from 1.2.2 to 1.3.1

Bumps [curb](https://github.com/taf2/curb) from 1.2.2 to 1.3.1.
- [Changelog](https://github.com/taf2/curb/blob/master/ChangeLog.md)
- [Commits](https://github.com/taf2/curb/commits)

---
updated-dependencies:
- dependency-name: curb
  dependency-version: 1.3.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -75,7 +75,7 @@ group :test do
 
   # Note: curb gem requires curl libraries
   # sudo apt-get install libcurl4-openssl-dev
-  gem 'curb', '~> 1.2'
+  gem 'curb', '~> 1.3'
 
   # Note: selenium-webdriver 3.x is incompatible with Firefox version 48 and prior
   # gem 'selenium' # Requires old version of selenium which is no longer available

Gemfile.lock

@@ -54,7 +54,7 @@ GEM
       fiber-annotation
       fiber-local (~> 1.1)
       json
-    curb (1.2.2)
+    curb (1.3.1)
     daemons (1.4.1)
     date (3.5.1)
     diff-lcs (1.6.2)
@@ -317,7 +317,7 @@ DEPENDENCIES
   async-dns (~> 1.4)
   browserstack-local (~> 1.4)
   capybara (~> 3.40)
-  curb (~> 1.2)
+  curb (~> 1.3)
   em-websocket (~> 0.5.3)
   erubis (~> 2.7)
   espeak-ruby (~> 1.1.0)