Remove gapic/core/artman_*.yaml as they have been reformed and moved to google/ directory (#472)

diff --git a/gapic/core/artman_appengine.yaml b/gapic/core/artman_appengine.yaml
deleted file mode 100644
index c6009f8..0000000
--- a/gapic/core/artman_appengine.yaml
+++ /dev/null
@@ -1,33 +0,0 @@
-common:
-  api_name: appengine
-  api_version: v1
-  package_type: grpc_common
-  packaging: google-cloud
-  organization_name: google
-  proto_deps:
-    - google-common-protos
-    - google-iam-v1
-  import_proto_path:
-    - ${GOOGLEAPIS}
-  src_proto_path:
-    - ${GOOGLEAPIS}/google/appengine/v1
-  output_dir: ${REPOROOT}/artman/output
-  gapic_api_yaml: []
-  service_yaml: []
-  git_repos:
-    staging:
-      location: git@github.com:googleapis/api-client-staging.git
-java:
-  git_repos:
-    staging:
-      paths:
-        - artifact: proto
-          dest: generated/java/proto-google-appengine
-        - artifact: grpc
-          dest: generated/java/grpc-google-appengine
-php:
-  git_repos:
-    staging:
-      paths:
-        - artifact: grpc
-          dest: generated/php/google-appengine
diff --git a/gapic/core/artman_core.yaml b/gapic/core/artman_core.yaml
deleted file mode 100644
index f71aaf0..0000000
--- a/gapic/core/artman_core.yaml
+++ /dev/null
@@ -1,39 +0,0 @@
-common:
-  api_name: common-protos
-  api_version: ""
-  package_type: grpc_common
-  packaging: google-cloud
-  organization_name: google
-  import_proto_path:
-    - ${GOOGLEAPIS}
-  src_proto_path:
-    - ${GOOGLEAPIS}/google/api
-    - ${GOOGLEAPIS}/google/cloud/audit
-    - ${GOOGLEAPIS}/google/logging/type
-    - ${GOOGLEAPIS}/google/longrunning
-    - ${GOOGLEAPIS}/google/rpc
-    - ${GOOGLEAPIS}/google/type
-  excluded_proto_path:
-    - ${GOOGLEAPIS}/google/api/servicemanagement
-    - ${GOOGLEAPIS}/google/api/servicecontrol
-  output_dir: ${REPOROOT}/artman/output
-  gapic_api_yaml: []
-  service_yaml: []
-  proto_deps: []
-  git_repos:
-    staging:
-      location: git@github.com:googleapis/api-client-staging.git
-java:
-  git_repos:
-    staging:
-      paths:
-        - artifact: proto
-          dest: generated/java/proto-google-common-protos
-        - artifact: grpc
-          dest: generated/java/grpc-google-common-protos
-php:
-  git_repos:
-    staging:
-      paths:
-        - artifact: grpc
-          dest: generated/php/google-common-protos
diff --git a/gapic/core/artman_iam.yaml b/gapic/core/artman_iam.yaml
deleted file mode 100644
index d853927..0000000
--- a/gapic/core/artman_iam.yaml
+++ /dev/null
@@ -1,33 +0,0 @@
-common:
-  api_name: iam
-  api_version: v1
-  organization_name: google
-  package_type: grpc_client
-  packaging: google-cloud
-  proto_deps:
-    - google-common-protos
-  import_proto_path:
-    - ${GOOGLEAPIS}
-  src_proto_path:
-    - ${GOOGLEAPIS}/google/iam/v1
-  output_dir: ${REPOROOT}/artman/output
-  gapic_api_yaml:
-    - ${GOOGLEAPIS}/google/iam/v1/iam_gapic.yaml
-  service_yaml: []
-  git_repos:
-    staging:
-      location: git@github.com:googleapis/api-client-staging.git
-java:
-  git_repos:
-    staging:
-      paths:
-        - artifact: grpc
-          dest: generated/java/grpc-google-iam-v1
-        - artifact: proto
-          dest: generated/java/proto-google-iam-v1
-php:
-  git_repos:
-    staging:
-      paths:
-        - artifact: grpc
-          dest: generated/php/google-iam-v1
diff --git a/gapic/core/artman_logging_external_types.yaml b/gapic/core/artman_logging_external_types.yaml
deleted file mode 100644
index 9818d5d..0000000
--- a/gapic/core/artman_logging_external_types.yaml
+++ /dev/null
@@ -1,38 +0,0 @@
-common:
-  api_name: logging-external-types
-  api_version: ""
-  package_type: grpc_common
-  packaging: google-cloud
-  organization_name: google
-  proto_deps:
-    - google-common-protos
-    - google-iam-v1
-    - google-appengine-v1
-  import_proto_path:
-    - ${GOOGLEAPIS}
-  src_proto_path:
-    - ${GOOGLEAPIS}/google/appengine/legacy
-    - ${GOOGLEAPIS}/google/appengine/logging/v1
-    - ${GOOGLEAPIS}/google/cloud/audit
-    - ${GOOGLEAPIS}/google/cloud/bigquery/logging/v1
-    - ${GOOGLEAPIS}/google/iam/v1/logging
-  output_dir: ${REPOROOT}/artman/output
-  gapic_api_yaml: []
-  service_yaml: []
-  git_repos:
-    staging:
-      location: git@github.com:googleapis/api-client-staging.git
-java:
-  git_repos:
-    staging:
-      paths:
-        - artifact: proto
-          dest: generated/java/proto-google-logging-external-types
-        - artifact: grpc
-          dest: generated/java/grpc-google-logging-external-types
-php:
-  git_repos:
-    staging:
-      paths:
-        - artifact: grpc
-          dest: generated/php/google-logging-external-types