fix bugs and update UGDG

[coveralls]

Pull Request Test Coverage Report for Build 356

• 0 of 11 (0.0%) changed or added relevant lines in 5 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.1%) to 70.191%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/main/java/seedu/address/logic/parser/DecryptCommandParser.java	0	1	0.0%
src/main/java/seedu/address/logic/commands/EncryptCommand.java	0	1	0.0%
src/main/java/seedu/address/storage/StorageManager.java	0	2	0.0%
src/main/java/seedu/address/commons/util/SecurityUtil.java	0	3	0.0%
src/main/java/seedu/address/logic/parser/EncryptCommandParser.java	0	4	0.0%
<!--	Total:	0	11	0.0%	-->

Files with Coverage Reduction	New Missed Lines	%
src/main/java/seedu/address/storage/StorageManager.java	1	58.54%
<!--	Total:	1		-->

Totals
Change from base Build 354:	0.1%
Covered Lines:	2456
Relevant Lines:	3499

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💛 - Coveralls