Add --dry-run option to simplify CI system integrations

Fixes: google#105.

Test Plan:

  $ git show --name-only HEAD | grep java$ | xargs -r gjf --dry-run
  Need Formatting:
    [gerrit-common/src/main/java/com/google/gerrit/common/IoUtil.java,\
     gerrit-server/src/main/java/com/google/gerrit/server/account/Emails.java]

Add --dry-run option to simplify CI system integrations

Fixes: google#105.

Test Plan:

  $ git show --name-only HEAD | grep java$ | xargs -r gjf --dry-run
  Need Formatting:
    [gerrit-common/src/main/java/com/google/gerrit/common/IoUtil.java,\
     gerrit-server/src/main/java/com/google/gerrit/server/account/Emails.java]

Add --dry-run option to simplify CI system integrations

Fixes: google#105.

Test Plan:

  $ git show --name-only HEAD | grep java$ | xargs -r gjf --dry-run
  Need Formatting:
    [gerrit-common/src/main/java/com/google/gerrit/common/IoUtil.java,\
     gerrit-server/src/main/java/com/google/gerrit/server/account/Emails.java]

1.3 release

1.2 release

1.1 release

1.0 release

[release] Bump versions to prep for release