Added spotbugs and errorprone plugins.

build.gradle

@@ -4,8 +4,12 @@ plugins {
     id "com.jfrog.bintray" version "1.8.3"
     id "com.github.ben-manes.versions" version "0.20.0"
     id "net.thauvin.erik.gradle.semver" version "0.9.5-beta"
+    id "com.github.spotbugs" version "1.6.2"
+    id "net.ltgt.errorprone" version "0.0.14"
 }
 
+
+import com.github.spotbugs.SpotBugsTask
 import org.apache.tools.ant.taskdefs.condition.Os
 
 defaultTasks 'check'
@@ -35,6 +39,7 @@ repositories {
 
 dependencies {
     compile 'com.github.spullara.mustache.java:compiler:0.9.5'
+    spotbugsPlugins 'com.h3xstream.findsecbugs:findsecbugs-plugin:1.7.1'
     testCompile 'org.testng:testng:6.14.3'
 }
 
@@ -137,6 +142,13 @@ test {
     useTestNG()
 }
 
+tasks.withType(SpotBugsTask) {
+    reports {
+        xml.enabled = false
+        html.enabled = true
+    }
+    excludeFilter = file("$projectDir/config/spotbugs/excludeFilter.xml")
+}
 compileJava {
     options.compilerArgs.add('-proc:none')
 }

config/spotbugs/excludefilter.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<FindBugsFilter
+        xmlns="https://github.com/spotbugs/filter/3.0.0"
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:schemaLocation="https://github.com/spotbugs/filter/3.0.0 https://raw.githubusercontent.com/spotbugs/spotbugs/3.1.0/spotbugs/etc/findbugsfilter.xsd">
+    <Match>
+        <Class name="net.thauvin.erik.semver.VersionProcessor"/>
+        <Or>
+            <Method name="writeTemplate"/>
+            <Method name="findValues"/>
+        </Or>
+        <Bug code="SECPTI"/>
+    </Match>
+</FindBugsFilter>

src/test/java/net/thauvin/erik/semver/VersionInfoTest.java

@@ -159,7 +159,7 @@ public class VersionInfoTest {
     }
 }
 
-@SuppressWarnings("ClassExplicitlyAnnotation")
+@SuppressWarnings({"ClassExplicitlyAnnotation", "BadAnnotationImplementation"})
 class VersionTest implements Version {
     @Override
     public Class<? extends Annotation> annotationType() {