iframe is now loaded when using google colab

[jnumainville]

Part of fix for #3

• Added logic to check if the script is being ran in google colab, then replace the server url with proxied url for the specified port if that is the case
• Tested in google colab, created a widget and verified that the iframe appeared

!apt-get install openjdk-11-jdk-headless

import os
from google.colab.output import eval_js
os.environ["JAVA_HOME"] = "/usr/lib/jvm/java-11-openjdk-amd64"

from google.colab import drive
drive.mount('/content/drive')

!pip install --upgrade pip setuptools wheel
!pip install deephaven-core deephaven-server
!pip install '/content/drive/MyDrive/deephaven_ipywidgets-0.2.0-py2.py3-none-any.whl'

import deephaven_server
from deephaven_server import Server
import portpicker
from google.colab.output import eval_js

dh_port = portpicker.pick_unused_port()
s = Server(port=dh_port, jvm_args=["-Xmx4g", "-Dhttp.requireHttp2=false"], dh_args={'http.requireHttp2': False})
s.start()

from google.colab import output
output.enable_custom_widget_manager()

from deephaven import empty_table
t = empty_table(10).update("x=i")

from deephaven_ipywidgets import DeephavenWidget
DeephavenWidget(t)