Speeds up lint and test in docker by keeping the cache between invocations. (#5177)

* Add a volume to store the tox cache on the host. This gives quite some speed boost when running lint_docker and test_docker.

* Only map .tox directory for cache.

script/lint

@@ -1,6 +1,8 @@
 #!/bin/sh
 # Execute lint to spot code mistakes.
 
+cd "$(dirname "$0")/.."
+
 if [ "$1" = "--changed" ]; then
   export files="`git diff upstream/dev --name-only | grep -e '\.py$'`"
   echo "================================================="

script/lint_docker

@@ -4,5 +4,10 @@
 # Stop on errors
 set -e
 
+cd "$(dirname "$0")/.."
+
 docker build -t home-assistant-test -f virtualization/Docker/Dockerfile.dev .
-docker run --rm -it home-assistant-test tox -e lint
+docker run --rm \
+    -v `pwd`/.tox/:/usr/src/app/.tox/ \
+    -t -i home-assistant-test \
+    tox -e lint

script/test

@@ -1,4 +1,6 @@
 #!/bin/sh
-# Excutes the tests with tox.
+# Executes the tests with tox.
+
+cd "$(dirname "$0")/.."
 
 tox -e py34

script/test_docker

@@ -1,8 +1,13 @@
 #!/bin/sh
-# Excutes the tests with tox in a docker container.
+# Executes the tests with tox in a docker container.
 
 # Stop on errors
 set -e
 
+cd "$(dirname "$0")/.."
+
 docker build -t home-assistant-test -f virtualization/Docker/Dockerfile.dev .
-docker run --rm -it home-assistant-test tox -e py35
+docker run --rm \
+    -v `pwd`/.tox/:/usr/src/app/.tox/ \
+    -t -i home-assistant-test \
+    tox -e py35