refactor: use platform to manage dependency

1. rename Packer.INSTANCE
2. gradle platform is a good thing (resolved #31)

tools/godzilla/build.gradle

@@ -0,0 +1,32 @@
+plugins {
+    id "io.freefair.lombok" version "8.11"
+}
+
+
+group = 'com.reajason.javaweb'
+version = ''
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}
+
+
+dependencies {
+    implementation project(":common")
+
+    implementation 'net.bytebuddy:byte-buddy'
+
+    implementation 'commons-io:commons-io'
+    implementation 'org.apache.commons:commons-lang3'
+    implementation 'commons-codec:commons-codec'
+
+    implementation 'com.squareup.okhttp3:okhttp'
+
+    testImplementation platform('org.junit:junit-bom')
+    testImplementation 'org.junit.jupiter:junit-jupiter'
+}
+
+test {
+    useJUnitPlatform()
+}