add gitlab oauth2

gitlab/build.gradle

@@ -0,0 +1,21 @@
+plugins {
+    id 'org.springframework.boot' version '2.6.6'
+    id 'io.spring.dependency-management' version '1.0.11.RELEASE'
+    id 'java'
+}
+
+group = 'example.oauth2'
+version = '1.0-SNAPSHOT'
+sourceCompatibility = JavaVersion.VERSION_11
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    implementation('org.springframework.boot:spring-boot-starter-web')
+    implementation('org.springframework.boot:spring-boot-starter-freemarker')
+
+    implementation('org.springframework.boot:spring-boot-starter-security')
+    implementation('org.springframework.security:spring-security-oauth2-client')
+}