Rename master branch to trunk in cassandra-dtest

 patch by Mick Semb Wever; reviewed by Brandon Williams for CASSANDRA-16166
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 5c9e72a..c881d1a 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -60,7 +60,7 @@
 
 ## Assertions
 
-- When possible, you should use the assert functions from [`tools/assertions.py`](https://github.com/apache/cassandra-dtest/blob/master/tools/assertions.py).
+- When possible, you should use the assert functions from [`tools/assertions.py`](https://github.com/apache/cassandra-dtest/blob/trunk/tools/assertions.py).
 - When none of these are applicable, use python's built in [unittest assertions](https://docs.python.org/2/library/unittest.html#assert-methods).
 
 ## Byteman Files
diff --git a/README.md b/README.md
index 3333219..9afa7b4 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,7 @@
 ### Python Dependencies
 There are multiple external Python dependencies required to run DTests. 
 The current Python dependency list is maintained in a file named
-[requirements.txt](https://github.com/apache/cassandra-dtest/blob/master/requirements.txt) 
+[requirements.txt](https://github.com/apache/cassandra-dtest/blob/trunk/requirements.txt)
 in the root of the `cassandra-dtest` repository.
 
 The easiest way to install these dependencies is with pip and virtualenv. 
diff --git a/linter_check.sh b/linter_check.sh
index fccb053..6e1acd9 100755
--- a/linter_check.sh
+++ b/linter_check.sh
@@ -7,11 +7,11 @@
 flake8_result=$?
 
 # lint all files for everything but line length errors
-git diff apache/master...HEAD -U0 | pycodestyle --ignore=E501 --diff
+git diff apache/trunk...HEAD -U0 | pycodestyle --ignore=E501 --diff
 pep8_style_check=$?
 
 # lint all files except json_test.py for line length errors
-git diff apache/master...HEAD -U0 | pycodestyle --diff --exclude='json_test.py' --exclude='meta_tests/assertion_test.py' --max-line-length=200
+git diff apache/trunk...HEAD -U0 | pycodestyle --diff --exclude='json_test.py' --exclude='meta_tests/assertion_test.py' --max-line-length=200
 pep8_line_length=$?
 
 echo -e "\nflake8 exited with ${flake8_result}."