Adding release checksum.
Added tag v0.5.0 for changeset ad66e8787738
Fix the name of the certs directory
Bump the minor version, update history
Use frozen string literals
Update my gem-signing cert
Added tag v0.4.1 for changeset 34884f2ed408
Added signature for changeset 7fa470aea04e
Bump the patch version, update history.
Fix more indentation warnings
Added tag v0.4.0 for changeset 1054bbc98239
Added signature for changeset fec56af1f0e4
Bump the minor version, update history.
Remove mixins only used in the specs.
Fix indentation warnings
Use Ruby 2.5 for development
Reflect reality in the README.
Added tag v0.3.0 for changeset cc6c1906a6a4