Merge branch 'add-checkstyle-plugin-and-config' into 'master'

config/checkstyle/checkstyle.xml

onionwrapper-android/build.gradle

...a/org/briarproject/onionwrapper/AndroidLocationUtils.java

...riarproject/onionwrapper/AndroidLocationUtilsFactory.java

...java/org/briarproject/onionwrapper/AndroidTorWrapper.java

onionwrapper-core/build.gradle

...ava/org/briarproject/onionwrapper/AbstractTorWrapper.java

...iarproject/onionwrapper/CircumventionProviderFactory.java

...ain/java/org/briarproject/onionwrapper/LocationUtils.java

...c/main/java/org/briarproject/onionwrapper/TorWrapper.java

onionwrapper-java/build.gradle

...java/org/briarproject/onionwrapper/JavaLocationUtils.java

...g/briarproject/onionwrapper/JavaLocationUtilsFactory.java