Master branch failing to build.

[rchatham]

After pulling and creating both .private-key.pem, .public-key.pem, and Makefile-secrets the repository is failing to build.

1. Run make images_build
2. Run make env_start
3. Run make web_build

I believe the ibmcom/kitura-ubuntu:latest image may be using a newer version of swift as a possible issue?

[rchatham]

I'm getting a bunch of issues around the use of someString.characters and it also gives the following error.

/src/.build/checkouts/Kitura.git-558333843415230329/Sources/Kitura/staticFileServer/FileServer.swift:96:48: error:
 cannot convert value of type 'ObjCBool' to expected argument type 'Bool'
                                  isDirectory: isDirectoryBool, response: response)
                                               ^~~~~~~~~~~~~~~
/src/.build/checkouts/Kitura.git-558333843415230329/Sources/Kitura/staticFileServer/FileServer.swift:134:21: error
: cannot convert value of type 'ObjCBool' to expected argument type 'Bool'
                if !isDirectoryBool {
                    ^~~~~~~~~~~~~~~