Bump fog-core from 2.1.0 to 2.3.0

Bumps [fog-core](https://github.com/fog/fog-core) from 2.1.0 to 2.3.0.
- [Release notes](https://github.com/fog/fog-core/releases)
- [Changelog](https://github.com/fog/fog-core/blob/master/changelog.md)
- [Commits](https://github.com/fog/fog-core/compare/v2.1.0...v2.3.0)

---
updated-dependencies:
- dependency-name: fog-core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -259,19 +259,19 @@ GEM
     ffi-compiler (1.0.1)
       ffi (>= 1.0.0)
       rake
-    fog-core (2.1.0)
+    fog-core (2.3.0)
       builder
-      excon (~> 0.58)
-      formatador (~> 0.2)
+      excon (~> 0.71)
+      formatador (>= 0.2, < 2.0)
       mime-types
     fog-json (1.2.0)
       fog-core
       multi_json (~> 1.10)
-    fog-openstack (0.3.10)
-      fog-core (>= 1.45, <= 2.1.0)
+    fog-openstack (0.3.2)
+      fog-core (~> 2.1)
       fog-json (>= 1.0)
       ipaddress (>= 0.8)
-    formatador (0.3.0)
+    formatador (1.1.0)
     fugit (1.7.1)
       et-orbi (~> 1, >= 1.2.7)
       raabro (~> 1.4)