HV-1550 Clarify the build output when checkstyle fails

When checkstyle failed, it used to fail in the initial, no-log
build, and then we didn't have the checkstyle logs to tell us why it
failed. By disabling checkstyle in this initial build we can make the
build fail a little bit later, when the logs are enabled.

Also, adding a separate checkstyle execution right before the actual
build allows us to fail fast if checkstyle checks fail.

.travis.yml

@@ -23,7 +23,9 @@ install:
   - mvn -N io.takari:maven:wrapper
   - ./mvnw -v
   # first run to download all the Maven dependencies without logging
-  - travis_wait ./mvnw $BUILD_OPTIONS -U -B -q -DskipTests=true install
+  - travis_wait ./mvnw $BUILD_OPTIONS -U -B -q -Dcheckstyle.skip -DskipTests=true install
 before_script:
 script:
-  - ./mvnw $BUILD_OPTIONS clean verify
+  - ./mvnw $BUILD_OPTIONS -DskipDistro=true checkstyle:check
+    && BUILD_OPTIONS+=' -Dcheckstyle.skip'
+    && ./mvnw $BUILD_OPTIONS clean verify