feat: acceptance tests

integration/build.gradle

@@ -0,0 +1,17 @@
+plugins {
+    id 'java'
+}
+
+group 'org.mobilitydata'
+version "gtfs-validator-${System.getenv("versionTag")}"
+
+sourceCompatibility = JavaVersion.VERSION_1_8
+compileTestJava.options.encoding = "UTF-8"
+
+repositories {
+    mavenCentral()
+}
+dependencies {
+    implementation project(':main')
+    testCompile group: 'junit', name: 'junit', version: '4.12'
+}

integration/src/main/java/org/mobilitydata/gtfsvalidator/integration/Main.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2021 MobilityData IO
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.mobilitydata.gtfsvalidator.integration;
+
+public class Main {
+  public static void main(String[] argv) {
+    org.mobilitydata.gtfsvalidator.cli.Main.main(argv);
+  }
+}

settings.gradle

@@ -2,3 +2,5 @@ rootProject.name = 'gtfs-validator'
 include 'core'
 include 'processor'
 include 'main'
+include 'integration'
+