Add unit test cases for JsonUtilsTest class
Respond useful links, logo url, website of each term and its skills
Merge pull request #105 from chrisshayan/Release11

Release11
Merge commit 'bbc3b15cb02b6de373f90f12639ddede193b9478'
Add skill data into JSON file for testing pop-up
Add empty data for testing empty logo
Merge commit 'bbc3b15cb02b6de373f90f12639ddede193b9478'
add useful link for term
Merge commit '7b37099624d3c17e839fe314576ef5e47007d797'
implement html for useful of skill popup and useful of term
Display empty logo if the term's logo is empty value in JSON
Display empty logo for term and skill if its value is empty