remove redundant config test and update build workflow

.github/workflows/build.yml

@@ -8,9 +8,9 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 1.8
+      - name: Set up JDK 11
         uses: actions/setup-java@v1
         with:
-          java-version: 1.8
+          java-version: 11
       - name: Build with Gradle
         run: ./gradlew build

bot/src/test/kotlin/dev/inmo/plagubot/config/ConfigTest.kt

@@ -1,40 +0,0 @@
-package dev.inmo.plagubot.config
-
-import dev.inmo.plagubot.HelloPlugin
-import kotlinx.serialization.InternalSerializationApi
-import org.junit.Test
-import kotlin.test.assertEquals
-
-class ConfigTest {
-    @InternalSerializationApi
-    @Test
-    fun testThatPluginPassedToParamsWillBeCorrectlyUsedInPlugins() {
-        val rawConfig = """
-            {
-              "database": {
-              },
-              "botToken": "",
-              "plugins": [
-                "helloPlugin"
-              ],
-              "params": {
-                "helloPlugin": {"type": "dev.inmo.plagubot.HelloPlugin", "parameter": "Example"}
-              }
-            }
-        """.trimIndent()
-        val config = configAndPluginsConfigJsonFormat.decodeFromString(PluginsConfigurationSerializer, rawConfig) as Config
-
-        assert(config.plugins.size == 1)
-        assert(config.plugins.first() is HelloPlugin)
-        assert((config.plugins.first() as HelloPlugin).parameter == "Example")
-
-        val redecoded = configAndPluginsConfigJsonFormat.decodeFromString(
-            PluginsConfigurationSerializer,
-            configAndPluginsConfigJsonFormat.encodeToString(PluginsConfigurationSerializer, config)
-        ) as Config
-        assertEquals(config.databaseConfig, redecoded.databaseConfig)
-        assertEquals(config.plugins, redecoded.plugins)
-        assertEquals(config.botToken, redecoded.botToken)
-        assertEquals(config.params ?.toMap(), redecoded.params ?.toMap())
-    }
-}