Embed Mixin, remove SpongeMixins dependency

This seemed to not work properly for me until I ran a `./gradlew clean`

.gitignore

@@ -31,7 +31,7 @@ Thumbs.db
 ## Jars
 *.jar
 !/gradle/wrapper/gradle-wrapper.jar
-!/libs/*.jar
+!/tools/mixin-0.8-SNAPSHOT.jar
 
 ### OSX (adds a lot of garbage)###
 .DS_Store

build.gradle

@@ -18,6 +18,11 @@ repositories {
 	}
 }
 
+configurations {
+    embed
+    compile.extendsFrom(embed)
+}
+
 apply plugin: 'forge'
 
 // Bump this every new code update after a version release, even if not releasing yet, that
@@ -37,7 +42,6 @@ compileJava {
 dependencies {
 	// Can use `compileOnly` instead of `compile` if you want to require it at build time,
 	// but not require it in `runClient`/`runServer`
-    compileOnly files("libs/SpongeMixins-1.3.0-dev.jar")
 	compile "codechicken:CodeChickenLib:1.7.10-1.1.3.140:dev"
 	compile "codechicken:CodeChickenCore:1.7.10-1.0.7.47:dev"
 	compile "codechicken:NotEnoughItems:1.7.10-1.0.5.120:dev"
@@ -137,7 +141,7 @@ repositories {
 }
 
 dependencies {
-    compile('org.spongepowered:mixin:0.7.11-SNAPSHOT') {
+    embed('org.spongepowered:mixin:0.7.11-SNAPSHOT') {
         // Mixin includes a lot of dependencies that are too up-to-date
         exclude module: 'launchwrapper'
         exclude module: 'guava'
@@ -159,6 +163,12 @@ jar {
         attributes.put("ForceLoadAsMod", true)
         attributes.put("MixinConfigs", yourMixinConfig)
     }
+
+    // embed libraries in jar
+    from configurations.embed.collect {
+        exclude '**/LICENSE.txt'
+        it.isDirectory() ? it : zipTree(it)
+    }
 }
 
 reobf {

src/main/java/ganymedes01/etfuturum/lib/Reference.java

@@ -5,7 +5,7 @@ public class Reference {
 	public static final String MOD_ID = "etfuturum";
 	public static final String MOD_NAME = "Et Futurum Requiem";
 	public static final String MOD_URL = "https://www.curseforge.com/minecraft/mc-mods/et-futurum-requiem";
-	public static final String DEPENDENCIES = "required-after:Forge@[10.13.4.1558,);required-after:spongemixins@[1.2.0,);after:Thaumcraft@[4.2.3.5,);after:TwilightForest;after:HardcoreEnderExpansion;";
+	public static final String DEPENDENCIES = "required-after:Forge@[10.13.4.1558,);after:Thaumcraft@[4.2.3.5,);after:TwilightForest;after:HardcoreEnderExpansion;";
 	public static final String VERSION_NUMBER = "2.2.2";