Authme Error

[15:20:49] [Server thread/ERROR]: Could not load 'plugins\AuthMe-5.0-SNAPSHOT.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.UnsupportedClassVersionError: fr/xephi/authme/AuthMe : Unsupported major.minor version 52.0
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:135) ~[spigot-1.8.3.jar:git-Spigot-870264a-0a645a2]
	at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:329) ~[spigot-1.8.3.jar:git-Spigot-870264a-0a645a2]
	at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [spigot-1.8.3.jar:git-Spigot-870264a-0a645a2]
	at org.bukkit.craftbukkit.v1_8_R2.CraftServer.loadPlugins(CraftServer.java:291) [spigot-1.8.3.jar:git-Spigot-870264a-0a645a2]
	at net.minecraft.server.v1_8_R2.DedicatedServer.init(DedicatedServer.java:199) [spigot-1.8.3.jar:git-Spigot-870264a-0a645a2]
	at net.minecraft.server.v1_8_R2.MinecraftServer.run(MinecraftServer.java:522) [spigot-1.8.3.jar:git-Spigot-870264a-0a645a2]
	at java.lang.Thread.run(Unknown Source) [?:1.7.0_79]
Caused by: java.lang.UnsupportedClassVersionError: fr/xephi/authme/AuthMe : Unsupported major.minor version 52.0
	at java.lang.ClassLoader.defineClass1(Native Method) ~[?:1.7.0_79]
	at java.lang.ClassLoader.defineClass(Unknown Source) ~[?:1.7.0_79]
	at java.security.SecureClassLoader.defineClass(Unknown Source) ~[?:1.7.0_79]
	at java.net.URLClassLoader.defineClass(Unknown Source) ~[?:1.7.0_79]
	at java.net.URLClassLoader.access$100(Unknown Source) ~[?:1.7.0_79]
	at java.net.URLClassLoader$1.run(Unknown Source) ~[?:1.7.0_79]
	at java.net.URLClassLoader$1.run(Unknown Source) ~[?:1.7.0_79]
	at java.security.AccessController.doPrivileged(Native Method) ~[?:1.7.0_79]
	at java.net.URLClassLoader.findClass(Unknown Source) ~[?:1.7.0_79]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:101) ~[spigot-1.8.3.jar:git-Spigot-870264a-0a645a2]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[spigot-1.8.3.jar:git-Spigot-870264a-0a645a2]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.7.0_79]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.7.0_79]
	at java.lang.Class.forName0(Native Method) ~[?:1.7.0_79]
	at java.lang.Class.forName(Unknown Source) ~[?:1.7.0_79]
	at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:64) ~[spigot-1.8.3.jar:git-Spigot-870264a-0a645a2]
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot-1.8.3.jar:git-Spigot-870264a-0a645a2]
	... 6 more