Remove Ubuntu Trusty support (EOL)

Author: Rulox

Makefile

@@ -2,7 +2,7 @@ GO_DOCKER_RUN = docker run --rm -v $(shell pwd):/go/src/github.com/nginxinc/ngin
 GOLANG_CONTAINER = golang:1.10
 BUILD_IN_CONTAINER = 1
 
-all: amazon centos7 ubuntu-trusty ubuntu-xenial amazon2 ubuntu-bionic
+all: amazon centos7 ubuntu-xenial amazon2 ubuntu-bionic
 
 test:
 ifeq ($(BUILD_IN_CONTAINER),1)
@@ -37,10 +37,6 @@ ubuntu-xenial: compile
 	make -C build/package/builders/ubuntu-xenial/
 	docker run --rm -v $(shell pwd)/build/package/debian:/debian -v $(shell pwd)/build_output:/build_output ubuntu-xenial-builder
 
-ubuntu-trusty: compile
-	make -C build/package/builders/ubuntu-trusty/
-	docker run --rm -v $(shell pwd)/build/package/debian:/debian -v $(shell pwd)/build_output:/build_output ubuntu-trusty-builder
-
 ubuntu-bionic: compile
 	make -C build/package/builders/ubuntu-bionic/
 	docker run --rm -v $(shell pwd)/build/package/debian:/debian -v $(shell pwd)/build_output:/build_output ubuntu-bionic-builder

README.md

@@ -43,7 +43,7 @@ Below you will find documentation on how to use nginx-asg-sync.
 
 We provide packages for the following operating systems:
 
-* Ubuntu: 14.04 (Trusty), 16.04 (Xenial), 18.04 (Bionic)
+* Ubuntu: 16.04 (Xenial), 18.04 (Bionic)
 * CentOS/RHEL: 7
 * Amazon Linux: 1, 2
 
@@ -163,7 +163,6 @@ where `<os>` is the target OS. The following values are allowed:
 * `amazon` for Amazon Linux 1
 * `amazon2` for Amazon Linux 2
 * `centos7` for CentOS7/RHEL7
-* `ubuntu-trusty` for Ubuntu 14.04
 * `ubuntu-xenial` for Ubuntu 16.04
 * `ubuntu-bionic` for Ubuntu 18.04