Add annotations (webmozarts#118)

Big thanks to @Ocramius for his work on this

.gitignore

@@ -1,2 +1,2 @@
-/vendor/
+vendor/
 composer.lock

.travis.yml

@@ -21,7 +21,9 @@ matrix:
     - php: 7.1
     - php: 7.2
     - php: 7.3
-      env: COVERAGE=yes
+      env:
+       - COVERAGE=yes
+       - ANALYSIS=yes
     - php: 7.4snapshot
     - php: hhvm-3.30
     - php: nightly
@@ -42,6 +44,8 @@ install:
 
 script:
   - if [[ $COVERAGE = yes ]]; then vendor/bin/phpunit --coverage-clover=coverage.clover; else vendor/bin/phpunit; fi
+  - if [[ $ANALYSIS = yes ]]; then composer i --working-dir=ci && ci/vendor/bin/psalm; fi
+
 
 after_script:
   - if [[ $COVERAGE = yes ]]; then wget https://scrutinizer-ci.com/ocular.phar && php ocular.phar code-coverage:upload --format=php-clover coverage.clover; fi

ci/composer.json

@@ -0,0 +1,5 @@
+{
+    "require": {
+        "vimeo/psalm": "^3.4"
+    }
+}

phpunit.xml.dist

@@ -9,6 +9,7 @@
     <testsuites>
         <testsuite name="Webmozart Assert Test Suite">
             <directory>./tests/</directory>
+            <exclude>./tests/static-analysis</exclude>
         </testsuite>
     </testsuites>
 

psalm.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0"?>
+<psalm
+    totallyTyped="true"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="https://getpsalm.org/schema/config"
+    xsi:schemaLocation="https://getpsalm.org/schema/config ci/vendor/vimeo/psalm/config.xsd"
+>
+    <projectFiles>
+        <directory name="tests/static-analysis" />
+        <ignoreFiles>
+            <directory name="vendor" />
+        </ignoreFiles>
+    </projectFiles>
+
+</psalm>