Sync console application version & add release Makefile

The console application reported a hardcoded version (5.0.0) that drifted
from the released git tags, so `./bin/soap-client` printed a stale version
(see phpro#611).

- Bump APP_VERSION to 6.1.0 to match the latest release.
- Add a Makefile `tag` target (modelled on phpro/grumphp) that rewrites
  APP_VERSION, lints, commits and creates a signed tag without the `v`
  prefix, keeping the constant and the tag in sync by construction.

Author: veewee

Makefile

@@ -0,0 +1,12 @@
+help:
+	@echo "Please use \`make <target>' where <target> is one of"
+	@echo "  tag            to modify the version and tag"
+
+tag:
+	$(if $(TAG),,$(error TAG is not defined. Pass via "make tag TAG=6.2.0"))
+	@echo Tagging $(TAG)
+	sed -i '' -e "s/APP_VERSION = '.*'/APP_VERSION = '$(TAG)'/" src/Phpro/SoapClient/Console/Application.php
+	php -l src/Phpro/SoapClient/Console/Application.php
+	git add -A
+	git commit -m '$(TAG) release' -n
+	git tag -s '$(TAG)' -m 'Version $(TAG)'

src/Phpro/SoapClient/Console/Application.php

@@ -20,7 +20,7 @@
 class Application extends SymfonyApplication
 {
     const APP_NAME = 'SoapClient';
-    const APP_VERSION = '5.0.0';
+    const APP_VERSION = '6.1.0';
 
     /**
      * Set up application: