GitLab

For a zero, it returns -Inf.
For a negative number, it returns NaN.

This is not exactly the same behavior as MATLAB's log function, because we want
to enforce type stability (i.e. never return a complex).

All dseries syntaxes now work under Octave, except ts{'variable'}(range) = value.

On MATLAB, importdata() is better at automatically guessing the delimiter.
Enforce tab delimiter to make it work on Octave.

Closes #39

As a consequence, no need to download the binary on the CI runners, since it is
already there.

It is possible to rename the dseries class. For instance, the
following is a valid syntax:

>> tseries = dseries();
>> tseries(ones(3,2))

ans is a dseries object:

   | Variable_1 | Variable_2
1Y | 1          | 1
2Y | 1          | 1
3Y | 1          | 1

It is also allowed to define a default starting period for the data passed
to the renamed dseries class/object:

>> tseries = dseries('1938M11')
>> tseries(ones(83,2))

ans is a dseries object:

        | Variable_1 | Variable_2
1938M11 | 1          | 1
1938M12 | 1          | 1
1939M1  | 1          | 1
1939M2  | 1          | 1
1939M3  | 1          | 1
1939M4  | 1          | 1
1939M5  | 1          | 1
1939M6  | 1          | 1
1939M7  | 1          | 1
1939M8  | 1          | 1
        |            |
1944M11 | 1          | 1
1944M12 | 1          | 1
1945M1  | 1          | 1
1945M2  | 1          | 1
1945M3  | 1          | 1
1945M4  | 1          | 1
1945M5  | 1          | 1
1945M6  | 1          | 1
1945M7  | 1          | 1
1945M8  | 1          | 1
1945M9  | 1          | 1

... a datafile which does not exist.

CI: simplification

See merge request !35

Was not correct when the testsuite crash.

Occuring when one of the inputs is not a dseries object.

(cherry picked from commit 5ac7ea053a682d8c86ecede0fcdbd1377e92a196)

Unless explicitely requested.

Should fix build error in travis-ci.