upstream-info: improve PyYAML.yaml

- trivial changes caused by
	manual created YAML ==>
	script created YAML

	+---
	 version_control: github
	-src_repo:  yaml/pyyaml
	+src_repo: yaml/pyyaml
	-separator: .
	+separator: "."

- bug fix

	-tag_prefix: ^v
	+tag_prefix: "^"

- add git_url (future manual input just needs this)

	+git_url: https://github.com/yaml/pyyaml.git

- add git tags, prefix-and-ordered by date

	+git_tag:
	+  - 2020-03-18 5.3.1
	+  - 2020-01-06 5.3
	+  - 2018-08-16 4.1-retracted
	+  - 2019-12-21 5.3b1
Signed-off-by: NLiu Shaofei <liushaofei5@huawei.com>
Signed-off-by: NWu Fengguang <wufengguang@huawei.com>

upstream-info/PyYAML.yaml

+---
 version_control: github
-src_repo:  yaml/pyyaml
-tag_prefix: ^v
-separator: .
+src_repo: yaml/pyyaml
+tag_prefix: "^"
+separator: "."
+git_url: https://github.com/yaml/pyyaml.git
+git_tag:
+  - 2020-03-18 5.3.1
+  - 2020-01-06 5.3
+  - 2018-08-16 4.1-retracted
+  - 2019-12-21 5.3b1
+  - 2019-11-25 5.2b1
+  - 2019-12-02 5.2
+  - 2019-03-08 5.1b7
+  - 2019-03-07 5.1b6
+  - 2019-03-07 5.1b5
+  - 2019-03-06 5.1b4
+  - 2019-02-27 5.1b3
+  - 2019-02-26 5.1b2
+  - 2019-02-24 5.1b1
+  - 2019-07-30 5.1.2
+  - 2019-06-06 5.1.1
+  - 2019-03-13 5.1
+  - 2018-06-29 4.2b2
+  - 2018-06-28 4.2b1
+  - 2018-06-26 4.1
+  - 2018-07-03 3.13rc1
+  - 2018-07-03 3.13b1
+  - 2018-07-05 3.13
+  - 2016-08-27 3.12
+  - 2014-03-26 3.11
+  - 2011-05-29 3.10
+  - 2009-08-30 3.09
+  - 2008-12-30 3.08
+  - 2008-12-28 3.07
+  - 2008-10-03 3.06
+  - 2007-05-12 3.05
+  - 2006-08-20 3.04
+  - 2006-06-18 3.03
+  - 2006-05-15 3.02
+  - 2006-05-07 3.01