Put at least two functions in the package and at least two tests

[SamTan111]

• Add two functions script in the package, within the directory of diabetes_analysis_pkg/diabetes_analysis_tools. This is part of the project requirement. See the project description for more details.
• Add dot-string to document the function
• Add one test for each function. put it under diabetes_analysis_pkg/diabetes_analysis_tools/tests. See the project description for more details.
• Run the package by using pip install diabetes_analysis_pkg/.
• Load the package by using import diabetes_analysis_tools OR from diabetes_analysis_tools import my_function_script