Remove the 'requirements.txt' syntax

This is needed because the syntax is only available under GPL v3.0,
which is not compatible with `bat`s license.

.gitmodules

@@ -113,9 +113,6 @@
 [submodule "assets/syntaxes/Org mode"]
 	path = assets/syntaxes/02_Extra/Org mode
 	url = https://github.com/jezcope/Org.tmbundle.git
-[submodule "assets/syntaxes/requirementstxt"]
-	path = assets/syntaxes/02_Extra/requirementstxt
-	url = https://github.com/wuub/requirementstxt
 [submodule "assets/syntaxes/DotENV"]
 	path = assets/syntaxes/02_Extra/DotENV
 	url = https://github.com/zaynali53/DotENV

CHANGELOG.md

@@ -35,6 +35,7 @@
 - Racket, see #1884 (@jubnzv)
 - LiveScript, see #1915 (@Enselic)
 - MediaWiki, see #1925 (@sorairolake)
+- The `requirements.txt` syntax has been removed due to incompatible license requirements.
 
 ## New themes
 

assets/syntaxes/02_Extra/requirementstxt.sublime-syntax

@@ -1,19 +0,0 @@
-%YAML 1.2
----
-# http://www.sublimetext.com/docs/3/syntax.html
-name: requirements.txt
-file_extensions:
-  - requirements.txt
-scope: source.requirementstxt
-contexts:
-  main:
-    - match: (#).*$\n?
-      scope: comment.line.requirementstxt
-      captures:
-        1: punctuation.definition.comment.requirementstxt
-    - match: '(?i)^[a-z0-9_\-\.]+'
-      scope: string.package_name.requirementstxt
-    - match: (?i)==|<|<=|>=|>
-      scope: keyword.operator.logical.punctuation.requirementstxt
-    - match: '(?i)\d+\.[\da-z\-_\.]*'
-      scope: constant.numeric.verions.requirementstxt

tests/syntax-tests/highlighted/RequirementsTXT/requirements.txt

@@ -1,8 +0,0 @@
-#this is a sample requirements.txt file
-
-django==11.2.0
-pywheels>=12.4 #a whitespace followed by comments
-Nuitka<0.6.8.4
-wxPython>=1.0, <=2.1
-
-#this is another comment

tests/syntax-tests/source/RequirementsTXT/requirements.txt

@@ -1,8 +0,0 @@
-#this is a sample requirements.txt file
-
-django==11.2.0
-pywheels>=12.4 #a whitespace followed by comments
-Nuitka<0.6.8.4
-wxPython>=1.0, <=2.1
-
-#this is another comment