Bump pstore from 0.1.4 to 0.2.0

Bumps [pstore](https://github.com/ruby/pstore) from 0.1.4 to 0.2.0.
- [Release notes](https://github.com/ruby/pstore/releases)
- [Commits](ruby/pstore@v0.1.4...v0.2.0)

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

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

Author: dependabot[bot]

Gemfile.lock

@@ -78,7 +78,7 @@ GEM
       racc
     pathname (0.4.0)
     power_assert (2.0.5)
-    pstore (0.1.4)
+    pstore (0.2.0)
     psych (4.0.6)
       stringio
     public_suffix (6.0.1)