Avoid schema duplication. Similar to fordfrog#265 from jschaf

src/main/java/cz/startnet/utils/pgdiff/schema/PgDatabase.java

@@ -137,14 +137,12 @@ public List<PgSchema> getSchemas() {
      * Adds {@code schema} to the lists of schemas.
      *
      * @param schema schema
-     * @throws ParserException Thrown if schema was already added to the database.
      */
     public void addSchema(final PgSchema schema) {
-        if (Objects.nonNull(schemas) && !schemas.isEmpty()) {
-            if (!schemas.contains(schema)) {
-                schemas.add(schema);
-            }
-        } else {
+
+        if (schemas.isEmpty()) {
+            schemas.add(schema);
+        } else if (!schemas.stream().filter(o -> o.getName().equals(schema.getName())).findFirst().isPresent()) {
             schemas.add(schema);
         }
     }

src/test/java/cz/startnet/utils/pgdiff/PgDiffTest.java

@@ -275,6 +275,7 @@ public static Collection<?> parameters() {
                   , {"alter_view_owner", false, false, false, false}
                   , {"grant_on_table_cols_mixed", false, false, false, false}
                   , {"grant_on_view_cols_mixed", false, false, false, false}
+                  , {"create_schema_no_change_table", false, false, false, false}      
                 });
     }
     /**

src/test/resources/cz/startnet/utils/pgdiff/create_schema_no_change_table_diff.sql

@@ -0,0 +1,2 @@
+
+

src/test/resources/cz/startnet/utils/pgdiff/create_schema_no_change_table_new.sql

@@ -0,0 +1,3 @@
+CREATE SCHEMA public;
+CREATE TABLE public.node (instance_id text);
+

src/test/resources/cz/startnet/utils/pgdiff/create_schema_no_change_table_original.sql

@@ -0,0 +1,3 @@
+CREATE SCHEMA public;
+CREATE TABLE public.node (instance_id text);
+