Fixed the color picker on page http://localhost:3000/s/1/level/37?level=4_2.
Updated required block number on Maze 2 Level 17.
Updated required block number on Maze 2 Level 18.
Fixed the rendering of obstacle.
Added back Turtle 1 Level 10's toolbox.
Corrected Turtle's play level continue button.
Merge pull request #96 from nanan9177/fix_color_picker

Commits that fix some bugs in Maze and Turtle