Update some build dependencies.

- Bump actions/checkout from 2.3.4 to 2.3.5 apache#188
- Bump mockito-core from 3.11.2 to 4.0.0 apache#187
- Bump junit-jupiter from 5.8.0-RC1 to 5.8.1 apache#186
- Bump maven-pmd-plugin from 3.14.0 to 3.15.0 apache#184

Author: garydgregory

src/changes/changes.xml

@@ -41,10 +41,13 @@
     <release version="1.9.1" date="2021-MM-DD" description="Feature and bug fix release (Java 8)">
       <!-- UPDATE -->
       <action                 type="update" dev="ggregory" due-to="Dependabot">Bump checkstyle from 8.44 to 9.0 #180.</action>
-      <action                 type="update" dev="ggregory" due-to="Dependabot">Bump junit-jupiter from 5.8.0-M1 to 5.8.0-RC1 #179.</action>
+      <action                 type="update" dev="ggregory" due-to="Dependabot">Bump junit-jupiter from 5.8.0-M1 to 5.8.1 #179, #186.</action>
       <action                 type="update" dev="ggregory" due-to="Dependabot">Bump jmh-core from 1.32 to 1.33 #176.</action>
       <action                 type="update" dev="ggregory" due-to="Dependabot">Bump jmh-generator-annprocess from 1.32 to 1.33 #175.</action>
       <action                 type="update" dev="ggregory" due-to="Dependabot">Bump commons.pmd-impl.version from 6.36.0 to 6.37.0 #173.</action>
+      <action                 type="update" dev="ggregory" due-to="Dependabot">Bump actions/checkout from 2.3.4 to 2.3.5 #188.</action>
+      <action                 type="update" dev="ggregory" due-to="Dependabot">Bump mockito-core from 3.11.2 to 4.0.0 #187.</action>
+      <action                 type="update" dev="ggregory" due-to="Dependabot">Bump maven-pmd-plugin from 3.14.0 to 3.15.0 #184.</action>
     </release>
     <release version="1.9.0" date="2021-07-24" description="Feature and bug fix release (Java 8)">
       <!-- FIX -->