add a facade

src/main/java/edu/kit/formatl/proofscriptparser/Facade.java

+package edu.kit.formatl.proofscriptparser;
+
+import edu.kit.formal.proofscriptparser.ScriptLanguageLexer;
+import edu.kit.formal.proofscriptparser.ScriptLanguageParser;
+import edu.kit.formatl.proofscriptparser.ast.ProofScript;
+import org.antlr.v4.runtime.*;
+
+/**
+ * @author Alexander Weigl
+ * @version 1 (27.04.17)
+ */
+public class Facade {
+    public ScriptLanguageParser.StartContext parseStream(CharStream stream) {
+        ScriptLanguageParser slp = new ScriptLanguageParser(new CommonTokenStream(new ScriptLanguageLexer(stream)));
+        return slp.start();
+    }
+
+}