Update some dependencies.

- Bump actions/cache from v2 to v2.1.4 apache#132.
- Bump maven-checkstyle-plugin from 3.1.1 to 3.1.2 apache#131.
- Bump mockito-core from 3.7.0 to 3.7.7 apache#129.

Author: garydgregory

src/changes/changes.xml

@@ -68,7 +68,9 @@
       <action                 type="update" dev="ggregory" due-to="Dependabot">Bump tests mockito-core from 3.4.6 to 3.5.11 #107, #110.</action>
       <action                 type="update" dev="ggregory" due-to="Dependabot">Bump build actions/setup-java from v1.4.0 to v1.4.3, #101, #113.</action>
       <action                 type="update" dev="ggregory" due-to="Dependabot">Bump maven-pmd-plugin from 3.13.0 to 3.14.0 #122.</action>
-      <action                 type="update" dev="ggregory" due-to="Dependabot">Bump mockito-core from 3.5.11 to 3.7.0, #123, #128.</action>
+      <action                 type="update" dev="ggregory" due-to="Dependabot">Bump mockito-core from 3.5.11 to 3.7.7, #123, #128, #129.</action>
+      <action                 type="update" dev="ggregory" due-to="Dependabot">Bump actions/cache from v2 to v2.1.4 #132.</action>
+      <action                 type="update" dev="ggregory" due-to="Dependabot">Bump maven-checkstyle-plugin from 3.1.1 to 3.1.2 #131.</action>
     </release>
     <release version="1.8" date="2020-02-01" description="Feature and bug fix release (Java 8).