perf: Remove semantic_version from the import tree

bench/app.py

@@ -11,7 +11,6 @@ import sys
 
 # imports - third party imports
 import click
-import semantic_version
 from six.moves import reload_module
 
 # imports - module imports
@@ -432,6 +431,8 @@ def get_version_from_string(contents, field='__version__'):
 	return match.group(2)
 
 def get_major_version(version):
+	import semantic_version
+
 	return semantic_version.Version(version).major
 
 def install_apps_from_path(path, bench_path='.'):

bench/config/redis.py

@@ -3,9 +3,6 @@ import os
 import re
 import subprocess
 
-# imports - third party imports
-import semantic_version
-
 # imports - module imports
 import bench
 from bench.config.common_site_config import get_config
@@ -62,6 +59,8 @@ def write_redis_config(template_name, context, bench_path):
 		f.write(template.render(**context))
 
 def get_redis_version():
+	import semantic_version
+
 	version_string = subprocess.check_output('redis-server --version', shell=True)
 	version_string = version_string.decode('utf-8').strip()
 	# extract version number from string

bench/utils.py

@@ -21,7 +21,6 @@ from distutils.spawn import find_executable
 
 # imports - third party imports
 import click
-from semantic_version import Version
 from six import iteritems
 
 # imports - module imports
@@ -89,6 +88,7 @@ def safe_decode(string, encoding = 'utf-8'):
 
 def check_latest_version():
 	import requests
+	from semantic_version import Version
 
 	try:
 		pypi_request = requests.get("https://pypi.org/pypi/frappe-bench/json")