nimble script incuded files inconsistent use with cache
Initial test:

```
# file: test1.nimble

include nimble_includes

version       = "0.1.0"
author        = "Me"
description   = "Test for nimble"
license       = "MIT"

# Dependencies

requires "nim >= 2.0.0"
```

```
# File: nimble_includes.nim

task test1, "First test for nimble":
  echo "Author: ", author
  echo "Description: ", description
  echo "project: ", projectName()
```

Now run `nimble test1`

Result is:
```
   Warning: Package 'test1' has an incorrect structure. The top level of the package source directory should contain at most one module, named 'test1.nim', but a file named 'nimble_includes.nim' was found. This will be an error in the future.
      Hint: If this is the primary source file in the package, rename it to 'test1.nim'. If it's a source file required by the main module, or if it is one of several modules exposed by 'test1', then move it into a 'test1/' subdirectory. If it's a test file or otherwise not required to build the the package 'test1.nim', prevent its installation by adding `skipFiles = @["nimble_includes.nim"]` to the .nimble file. See https://github.com/nim-lang/nimble#libraries for more info.
  Verifying dependencies for test1@0.1.0
  Executing task test1 in /home/ggb/Temp/nim/test1/test1.nimble
Author: 
Description: 
project: test1
```

This works, to a degree, but does not show a description or author because the include statement is before the assignment of author and description, so I change that:

```
# file: test1.nimble

version       = "0.1.0"
author        = "Me"
description   = "Test for nimble"
license       = "MIT"

include nimble_includes

# Dependencies

requires "nim >= 2.0.0"
```

The output seems reasonable:

```
   Warning: Package 'test1' has an incorrect structure. The top level of the package source directory should contain at most one module, named 'test1.nim', but a file named 'nimble_includes.nim' was found. This will be an error in the future.
      Hint: If this is the primary source file in the package, rename it to 'test1.nim'. If it's a source file required by the main module, or if it is one of several modules exposed by 'test1', then move it into a 'test1/' subdirectory. If it's a test file or otherwise not required to build the the package 'test1.nim', prevent its installation by adding `skipFiles = @["nimble_includes.nim"]` to the .nimble file. See https://github.com/nim-lang/nimble#libraries for more info.
  Verifying dependencies for test1@0.1.0
  Executing task test1 in /home/ggb/Temp/nim/test1/test1.nimble
Author: Me
Description: Test for nimble
project: test1
```

But it seems to work because the task ``test1`` has been cached.

When I change the task name to ``test2`` so as to invalidate the cache:

```
# File: nimble_includes.nim

task test2, "First test for nimble":
  echo "Author: ", author
  echo "Description: ", description
  echo "project: ", projectName()
```

And now run `nimble test2`

I now receive the error:

```
   Warning: Package 'test1' has an incorrect structure. The top level of the package source directory should contain at most one module, named 'test1.nim', but a file named 'nimble_includes.nim' was found. This will be an error in the future.
      Hint: If this is the primary source file in the package, rename it to 'test1.nim'. If it's a source file required by the main module, or if it is one of several modules exposed by 'test1', then move it into a 'test1/' subdirectory. If it's a test file or otherwise not required to build the the package 'test1.nim', prevent its installation by adding `skipFiles = @["nimble_includes.nim"]` to the .nimble file. See https://github.com/nim-lang/nimble#libraries for more info.
       Tip: 1 messages have been suppressed, use --verbose to show them.
nimble.nim(2130)         doAction

    Error:  Could not find task test2 in /home/ggb/Temp/nim/test1/test1.nimble
     Hint:  Run `nimble --help` and/or `nimble tasks` for a list of possible commands.
```