Fix file extension replacement in node module

[parasyte]

Rebase for #138

I discovered a bug with filename extension removal in dot.process when using additional . characters in the filename. Example directory structure:

src/video/webgl/glsl/
|-- fragment.glsl.dot
`-- vertex.glsl.dot

Processed with:

console.log(Object.keys(dot.process({
    src : "src/video/webgl/glsl/"
})));

Outputs the following keys:

["fragment", "vertex"]

The expected "glsl" extension has been removed. The patch fixes this issue by using String.prototype.replace instead of locating the first . character.

[coveralls]

Coverage decreased (-9.3%) to 88.8% when pulling 69eede2 on parasyte:bug/replace-ext-rebase into e7accbf on olado:master.

[epoberezkin]

@parasyte thank you. let me review and I will merge. Don't worry about coverage getting down - it's actually better now as another file has the test.

[epoberezkin]

I like the change, but given that the way it works now is, arguably, "a feature" and this change may break some users' code, the change should go in v2. I think it's time to create a branch for v2 and we can release it to npm as beta. Please give me some time - I will let you know.

[epoberezkin]

@parasyte It would be helpful if you could submit some passing test, without code changes, as a separate PR in the meanwhile.

[epoberezkin]

@parasyte just created branch v2.0.0. Please submit:

• the test that passes without the changes to the master branch
• an additional test (that fails without changes) and the change to branch v2.0.0

Then I can merge it all and deploy 2.0.0 as beta version