Split CI build into two jobs

This makes it easier to see the cause of a build failure at a glance.

Author: per1234

.travis.yml

@@ -1,31 +1,33 @@
 # This file is used to configure the Travis CI tests for this repository
 
-sudo: false
-
-
-# It's necessary to do this just for codespell
-language: python
-python: 3.6
-
-
-script:
-  # Formatting checks:
-  # Check for files starting with a blank line
-  - find . -path ./.git -prune -o -type f -print0 | xargs -0 -L1 bash -c 'head -1 "$0" | grep --regexp="^$"; if [[ "$?" == "0" ]]; then echo "Blank line found at start of $0."; false; fi'
-  # Check for tabs
-  - "if grep --line-number --recursive --binary-files=without-match --exclude-dir=.git --regexp=$'\t' .; then echo 'Tab found.'; false; fi"
-  # Check for trailing whitespace
-  - "if grep --line-number --recursive --binary-files=without-match --exclude-dir=.git --regexp='[[:blank:]]$' .; then echo 'Trailing whitespace found.'; false; fi"
-  # Check for non-Unix line endings
-  - "if grep --files-with-matches --recursive --binary-files=without-match --exclude-dir=.git --regexp=$'\r$' .; then echo 'Non-Unix EOL detected.'; false; fi"
-  # Check for blank lines at end of files
-  - find . -path ./.git -prune -o -type f -print0 | xargs -0 -L1 bash -c 'tail -1 "$0" | grep --regexp="^$"; if [[ "$?" == "0" ]]; then echo "Blank line found at end of $0."; false; fi'
-  # Check for files that don't end in a newline (https://stackoverflow.com/a/25686825)
-  - find . -path ./.git -prune -o -type f -print0 | xargs -0 -L1 bash -c 'if test "$(tail --bytes=1 "$0")"; then echo "No new line at end of $0."; false; fi'
-
-  # Check for typos
-  - pip install codespell
-  - codespell --skip="${TRAVIS_BUILD_DIR}/.git" "${TRAVIS_BUILD_DIR}"
+env:
+matrix:
+  include:
+  - name: "Formatting checks"
+    language: minimal
+    script:
+      # Formatting checks:
+      # Check for files starting with a blank line
+      - find . -path ./.git -prune -o -type f -print0 | xargs -0 -L1 bash -c 'head -1 "$0" | grep --regexp="^$"; if [[ "$?" == "0" ]]; then echo "Blank line found at start of $0."; false; fi'
+      # Check for tabs
+      - "if grep --line-number --recursive --binary-files=without-match --exclude-dir=.git --regexp=$'\t' .; then echo 'Tab found.'; false; fi"
+      # Check for trailing whitespace
+      - "if grep --line-number --recursive --binary-files=without-match --exclude-dir=.git --regexp='[[:blank:]]$' .; then echo 'Trailing whitespace found.'; false; fi"
+      # Check for non-Unix line endings
+      - "if grep --files-with-matches --recursive --binary-files=without-match --exclude-dir=.git --regexp=$'\r$' .; then echo 'Non-Unix EOL detected.'; false; fi"
+      # Check for blank lines at end of files
+      - find . -path ./.git -prune -o -type f -print0 | xargs -0 -L1 bash -c 'tail -1 "$0" | grep --regexp="^$"; if [[ "$?" == "0" ]]; then echo "Blank line found at end of $0."; false; fi'
+      # Check for files that don't end in a newline (https://stackoverflow.com/a/25686825)
+      - find . -path ./.git -prune -o -type f -print0 | xargs -0 -L1 bash -c 'if test "$(tail --bytes=1 "$0")"; then echo "No new line at end of $0."; false; fi'
+
+  - name: "Spell check"
+    language: python
+    python: 3.6
+    install:
+      # https://github.com/codespell-project/codespell
+      - pip install codespell
+    script:
+      - codespell --skip="${TRAVIS_BUILD_DIR}/.git" "${TRAVIS_BUILD_DIR}"
 
 
 notifications: