Removing s3mock

[jglick]

#265 failed with internal dependency issues in S3Mock. Rather than work to maintain this dep, just removing it. Was only used in one test introduced in #62. As it turns out, #109 added another test of the same functionality

artifact-manager-s3-plugin/src/test/java/io/jenkins/plugins/artifact_manager_jclouds/s3/MinioIntegrationTest.java

Lines 153 to 162 in d98e616

	@Test
	public void canCreateBucket() throws Throwable {
	rr.then(new WithMinioServiceEndpoint(MinioIntegrationTest::_canCreateBucket));
	}
	private static void _canCreateBucket(JenkinsRule r) throws Throwable {
	String testBucketName = "jenkins-ci-data";
	Bucket createdBucket = config.createS3Bucket(testBucketName);
	assertEquals(testBucketName, createdBucket.getName());
	client.headBucket(new HeadBucketRequest(testBucketName));
	}

which at least runs against an actual S3-compatible server with authentication and so is more convincing. Other interesting stuff to test would be disableSessionToken, use of acceleration, etc., which would require

artifact-manager-s3-plugin/src/test/java/io/jenkins/plugins/artifact_manager_jclouds/s3/S3AbstractTest.java

Lines 63 to 75 in d98e616

	@BeforeClass
	public static void live() {
	assumeThat("define $S3_BUCKET as explained in README", S3_BUCKET, notNullValue());
	assumeThat("define $S3_DIR as explained in README", S3_DIR, notNullValue());
	try {
	AmazonS3ClientBuilder builder = AmazonS3ClientBuilder.standard();
	assumeTrue(S3_BUCKET + " bucket does not exist", builder.build().doesBucketExistV2(S3_BUCKET));
	assumeThat("can get credentials from environment", builder.getCredentials().getCredentials(), notNullValue());
	} catch (SdkClientException x) {
	x.printStackTrace();
	assumeNoException("failed to connect to S3 with current credentials", x);
	}
	}