Add updated meta dependency.

[ccasey645]

Add updated ICU download URL after ICU dependency's tgz file was migrated from Subversion repo to GitHub repo (source: http://site.icu-project.org/repository).

Purpose: Metapy's Python wheel install process runs the Meta repo's cmake build process. The Meta repo's cmake steps will fail to download the ICU dependency because the old URL for the ICU dependency does not have the Tar file anymore. Without this updated URL that has the ICU dependency Meta needs to build, no-one can make builds of Meta and by extension, the Metapy repo cannot make new builds for Python 3.8 and Python 3.9 which are currently needed (but missing because of this bug).

[dmcguire81]

@smassung or @skystrife can you add additional collaborators to this repository, so that it can be actively maintained? We're still using versions of Python that have long since reached end-of-life (Python 2.7 and 3.5) in CS 410 because this fix can't get merged. Good candidates would be any of the current term's TA's contributing to the Development of Assignments in metapy:

• @assmaboughoula
• @kevinros
• @liuyuxiang512
• @priyanka-dey or @priyanka-dey-19