remove binary name from docker image tag

the binary file name is unnecessary since only one binary file is generated

.gitlab-ci.yml

@@ -53,21 +53,21 @@ build:
 build-tagged-image:
   extends: .build-image
   variables:
-    IMAGE_TAG: "$CI_REGISTRY_IMAGE:$BIN_NAME-$CI_COMMIT_TAG"
+    IMAGE_TAG: "$CI_REGISTRY_IMAGE:$CI_COMMIT_TAG"
   only:
     - tags
 
 build-latest-image:
   extends: .build-image
   variables:
-    IMAGE_TAG: "$CI_REGISTRY_IMAGE:$BIN_NAME-latest"
+    IMAGE_TAG: "$CI_REGISTRY_IMAGE:latest"
   only:
     - master
 
 build-feature-branch-image:
   extends: .build-image
   variables:
-    IMAGE_TAG: "$CI_REGISTRY_IMAGE:$BIN_NAME-$CI_COMMIT_REF_NAME"
+    IMAGE_TAG: "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_NAME"
   except:
     - master
     - tags