Add some regression tests for setting pragmas

This commit just adds some test cases around the pragma APIs

Author: tenderlove

lib/sqlite3/database.rb

@@ -196,7 +196,7 @@ def initialize file, options = {}, zvfs = nil
     #
     # Fetch the encoding set on this database
     def encoding
-      prepare("PRAGMA encoding") { |stmt| Encoding.find(stmt.first.first) }
+      Encoding.find super
     end
 
     # Installs (or removes) a block that will be invoked for every access

test/test_pragmas.rb

@@ -27,6 +27,18 @@ def teardown
       @db.close
     end
 
+    def test_temp_store_mode
+      @db.temp_store = "memory"
+      assert_equal 2, @db.temp_store
+      @db.temp_store = 1
+      assert_equal 1, @db.temp_store
+    end
+
+    def test_encoding
+      @db.encoding = "utf-16le"
+      assert_equal Encoding.find("utf-16le"), @db.encoding
+    end
+
     def test_pragma_errors
       assert_raises(SQLite3::Exception) do
         @db.set_enum_pragma("foo", "bar", [])