[TASK] Restructure tests/ folder.

Move unit tests to tests/unit/. Get the old still working UnitTests
into a working state again.
Updated composer.json with required-dev packages.
Create a new folder tests/acceptance for Behat functional/acceptance
testing. Add a first Feature draft of a Behat functional test for
local login.

composer.json

@@ -27,8 +27,15 @@
 		"ext-gd" : "*",
 		"ext-mbstring" : "*",
 		"ext-xml" : "*",
-		"sabre/dav" : "~3.2",
-		"ext-openssl" : "*"
+		"ext-openssl" : "*",
+		"sabre/dav" : "~3.2"
+	},
+	"require-dev" : {
+		"php" : ">=5.6",
+		"phpunit/phpunit" : "^5.6",
+		"behat/behat" : "@stable",
+		"behat/mink-extension": "@stable",
+		"behat/mink-goutte-driver": "@stable"
 	},
 	"autoload" : {
 		"psr-4" : {
@@ -36,8 +43,13 @@
 			"Zotlabs\\" : "Zotlabs/"
 		}
 	},
+	"autoload-dev" : {
+		"psr-4" : {
+			"Zotlabs\\Tests\\Unit\\" : "tests/unit"
+		}
+	},
 	"minimum-stability" : "stable",
 	"config" : {
 		"notify-on-install" : false
 	}
-}
+}