To make a new release:

* bump versionCode and versionName in app/build.gradle
* update NEWS
* make sure everything is commited and make a signed tag
* ./gradlew assembleRelease
* sign the apk using jarsigner:
jarsigner -digestalg SHA1 -sigalg MD5withRSA -verbose -providerClass sun.security.pkcs11.SunPKCS11 -providerArg /etc/pkcs11_java.cfg -keystore NONE -storetype PKCS11 app.apk "Certificate for PIV Authentication"
* zipalign the signed apk:
zipalign -v 4 unaligned.apk aligned.apk
* if happy with the release: git push && git push --tags
* copy APK to site, create signature, publish.
