fixed all links and images for google colab

Author: GokuMohandas

images/bulb.gif

@@ -21,8 +21,7 @@
         "colab_type": "text"
       },
       "source": [
-        "<a href=\"https://practicalai.me\"><img src=\"https://raw.githubusercontent.com/practicalAI/practicalAI/master/images/practicalai_header_logo.png\" align=\"left\" hspace=\"20px\" vspace=\"5px\"></a>\n",
-        "\n",
+        "<a href=\"https://practicalai.me\"><img height=\"80\" src=\"https://raw.githubusercontent.com/practicalAI/practicalAI/master/images/practicalai_logo.png\" align=\"left\" hspace=\"20px\" vspace=\"5px\"></a>\n",
         "<img src=\"https://raw.githubusercontent.com/practicalAI/practicalAI/master/images/colab.png\" width=170 align=\"right\">\n",
         "\n",
         "<h1>Notebook Basics</h1>\n",
@@ -39,7 +38,7 @@
       "source": [
         "<table align=\"left\">\n",
         "  <td>\n",
-        "      <img src=\"https://raw.githubusercontent.com/practicalAI/practicalAI/master/images/practicalai_small_logo.png\">\n",
+        "      <img src=\"https://raw.githubusercontent.com/practicalAI/practicalAI/master/images/practicalai_logo.png\" height=\"20\">\n",
         "      <a target=\"_blank\" href=\"https://practicalai.me\">View on practicalAI</a>\n",
         "  </td>\n",
         "  <td>\n",
@@ -261,6 +260,7 @@
       "source": [
         "---\n",
         "<br>\n",
+        "<img height=\"25\" src=\"https://raw.githubusercontent.com/practicalAI/practicalAI/master/images/twitter.gif\" align=\"left\" vspace=\"17px\" hspace=\"17px\">\n",
         "\n",
         "Subscribe to our [newsletter](https://practicalai.me/#newsletter) and follow us on social media to get the latest updates! <br><div><a class=\"ai-header-badge\" target=\"_blank\" href=\"https://github.com/GokuMohandas/practicalAI\">\n",
         "              <img src=\"https://img.shields.io/github/stars/GokuMohandas/practicalAI.svg?style=social&label=Star\">\n",