Rename database client classes

Update our class names to reflect the new file structure introduced in
b700c1bef89a67a64f1040fb6bb03c0320eefe91.

Use the

    module DBShell
      module Client
      end
    end

syntax intead of `DBShell::Client` so that we don't have to define the
`Client` module in a separate file and require it. Otherwise we'd get an
error:

    lib/dbshell/client/sqlite3.rb:1:in `<top (required)>': uninitialized constant DBShell::Client (NameError)

1 files changed, 19 insertions, 15 deletions

diff --git a/lib/dbshell/client/database.rb b/lib/dbshell/client/database.rb
index d77efce..35cb9ee 100644
--- a/lib/dbshell/client/database.rb
+++ b/lib/dbshell/client/database.rb
@@ -1,22 +1,26 @@
 require 'dbshell/client/sqlite3'
 require 'dbshell/client/postgres'
 
-class DBShell::DatabaseClient
-  def self.handler(connection_params)
-    case connection_params['adapter']
-    when 'sqlite3'
-      DBShell::Sqlite3Client
-    when 'postgresql'
-      DBShell::PostgresClient
-    else
-      raise DBShell::InvalidDatabaseAdapter
-    end
-  end
+module DBShell
+  module Client
+    class Database
+      def self.handler(connection_params)
+        case connection_params['adapter']
+        when 'sqlite3'
+          DBShell::Client::Sqlite3
+        when 'postgresql'
+          DBShell::Client::Postgres
+        else
+          raise DBShell::InvalidDatabaseAdapter
+        end
+      end
 
-  def self.runshell(connection_params)
-    self
-      .handler(connection_params)
-      .runshell(connection_params)
+      def self.runshell(connection_params)
+        self
+          .handler(connection_params)
+          .runshell(connection_params)
+      end
+    end
   end
 end