Add install step for Homebrew.

Makefile

@@ -1,14 +1,16 @@
-SWIFT_BUILD_FLAGS=-Xswiftc "-target" -Xswiftc "x86_64-apple-macosx10.12"
+BUILD_FLAGS=-Xswiftc "-target" -Xswiftc "x86_64-apple-macosx10.12"
+RELEASE_BUILD_FLAGS=$(BUILD_FLAGS) -c release -Xswiftc -static-stdlib --disable-sandbox
+RELEASE_EXECUTABLE=$(shell swift build $(RELEASE_BUILD_FLAGS) --show-bin-path)/periphery
 
 .PHONY: all $(MAKECMDGOALS)
 
 all: build
 
 build:
-	@swift build $(SWIFT_BUILD_FLAGS)
+	@swift build $(BUILD_FLAGS)
 
-release:
-	@swift build -c release -Xswiftc -static-stdlib $(SWIFT_BUILD_FLAGS)
+build_release:
+	@swift build $(RELEASE_BUILD_FLAGS)
 
 proj: build
 	@rm -rf Periphery.xcodeproj
@@ -20,4 +22,8 @@ lint:
 	@swiftlint lint --quiet
 
 test:
-	@set -o pipefail && swift test $(SWIFT_BUILD_FLAGS) 2>&1 | bundle exec xcpretty -tc
+	@set -o pipefail && swift test $(BUILD_FLAGS) 2>&1 | bundle exec xcpretty -tc
+
+install: build_release
+	install -d "$(PREFIX)/bin/"
+	install "$(RELEASE_EXECUTABLE)" "$(PREFIX)/bin/"

scripts/release

@@ -37,7 +37,7 @@ git push origin master
 git push origin ${version}
 
 rm -rf .build/release/periphery
-make release
+make build_release
 rm -rf .release
 mkdir .release
 cp .build/release/periphery .release/