Bump options from 1.0.5 to 2.0.0

Bumps [options](https://github.com/plume-lib/options) from 1.0.5 to 2.0.0.
- [Release notes](https://github.com/plume-lib/options/releases)
- [Changelog](https://github.com/plume-lib/options/blob/master/CHANGELOG.md)
- [Commits](plume-lib/options@v1.0.5...v2.0.0)

---
updated-dependencies:
- dependency-name: org.plumelib:options
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

build.gradle

@@ -50,7 +50,7 @@ dependencies {
     compile files("${checkerJar}")
     compile group: 'com.google.errorprone', name: 'javac', version: "$errorproneJavacVersion"
 
-    compile 'org.plumelib:options:1.0.5'
+    compile 'org.plumelib:options:2.0.0'
     // Serialize constraints
     compile 'com.googlecode.json-simple:json-simple:1.1.1'
     // Pretty print serialized constraints